The reformists have completely lost the loyalty of their supporters. If Khamenei can't sideline them now, then he can never sideline them; which means that the reformists will continue to act as enemy's fifth column inside Iran. In that case, the blame will be on Khamenei, not anyone else.
Reformists - as well as the centrist pragmatists, whom are technically a distinct faction from the reformists, have lost the trust of "grey spectrum" voters, i. e. of voters with no specific party-political affiliation whom were fooled into electing them last time around with the false promise that improved relations with the west are going to solve all of Iran's economic woes.
But their engaged, ideological support base still remains. As well as their influence within the state apparatus, key stretches of the economy (including some of Iran's major industries and agricultural enterprises, the banking and finacial sector etc) and last but not least, the systematic backing they enjoy from western-based media religiously followed by a considerable segment of the Iranian population, with these media campaigning for reformist / centrist candidates at every election.
That still makes for a large amount of political capital, enough to turn the country upside down if they feel cornered too much, and enough to prevent the Supreme Leader from delivering them the coup de grace. But not enough to bring their agenda to the desired conclusion.
There's also another factor one needs to take into account: under certain circumstances, it might be more advisable to co-opt a rivalling established faction than to drive it outside of the system. As long as the liberals have their share of power, although never enough to fully have their way, they will not openly and directly call for popular upheaval aimed at "regime change" - and we all know how in case of such major instability gripping the country, Iran will be finished, since foreign enemies will jump in to exploit the opportunity by propping up all manner of armed revolt and separatism.
If liberals are ousted from the system altogether, chances are they will not just radicalize their positions but also their tactics: instead of trying to implement their agenda in a creeping and duplicitous manner - which so far the Supreme Leader has managed to prevent from reaching its ultimate goals, they'd take the system on frontally. And that in turn, might prove to be the straw that breaks the camel's back because it would array too large and too integrated of a coalition (in-house reformists + in-house centrists + exiled opposition + separatist terrorists acting in perfect alliance with each other) against the state.
Khamenei does not need a military coup to overthrow Rouhani. A stroke of pen is sufficient for that. And it is not unprecedented. Khomeini ousted Bani Sadr for much less than what Rouhani has done so far. What did Bani Sadr do that Rouhani hasn't done worse already?
Technically, a stroke of a pen would suffice but that stroke of a pen would engender heavy political consequences fraught with enormous risk for Iran's stability.
The Iran of the early revolutionary period and the Iran of today are considerably different places. Much has changed since then.
* Imam Khomeini was the one who led a successful Revolution, overthrowing the old political order and replacing it with a new one. This confers a leader immense legitimacy and popular support. As much as I hate to say it, the current Supreme Leader does not enjoy the same amount of popular backing (although contrary to anti-IR propagandist, I have no doubt a good majority are loyal to him).
* Every revolution is marked by much greater degrees of fervor and radicalism in its initial phase compared to later stages of its history. From a sociological point of view, this is verifiable in the case of other major revolutions accross the world, regardless of their ideological orientation. Iran's no exception. With the radicalism prevailing in the 80's, it was far more feasible for the Supreme Leader to oust the president by decree than it is for the present day Supreme Leader.
* Iranian society itself has changed. 24/7 propaganda from abroad on a scale unheard of in human history, as well as "tahaajome farhangi" by the west have resulted in a situation where liberal and western-apologetic thinking has spread far and wide in Iranian society.
We must realize that some 40% of Iranians (if I were to have a wild guess) do not even have real patriotic or Islamic revolutionary views. In the 80's however, maybe 10% of the population, at most, were liberals or apologetic of Iran's western enemies. Imagine the stakes of abruptly and comprehensively suppressing the liberal in-house faction under current social circumstances. These are just not comparable with the 80's.
Why did the IR allow some parts of the population to be brainwashed by western(-based) media? Simple, the alternative would have been to completely enforce the ban on satellite TV receivers and, more importantly, not to introduce the internet in Iran.
* What influence did Bani Sadr enjoy within the system? Was he linked to a major component of the establishment? Not really. At most, he was indirectly associated with the MKO and their minor allies (Jebheye Melliye Demokraat of Hedaayat Matin Daftari, Kurdish ethnicist parties and so on).
Well, not only could these not be considered real heavy weights within the system (they were actually located at the margins of the Islamic Republic, not sharing its predominant ideology and fielding their own referential leaders apart from Imam Khomeini), but even so it took a bloody albeit relatively small scale civil war (with tens of thousands of victims nonetheless) to defeat this block.
The present day reformists and centrists are a different pair of shoes. They alone represent half the establishment of the IR. Uprooting them will prove significantly harder than ousting Bani Sadr and the MKO. A leadership decree demanding the president to resign, would not be an ideal way to go about this anyway (especially since Rohani is already a sitting duck and is almost guaranteed to be succeeded by a principlist next year). The backlash that would ensue after a sidelining of contemporary establishment liberals would be more consequential by magnitudes than the reaction to Bani Sadr's ousting.
And then there was the imposed war against Saddam's Iraq, of course. Which acted as a hugely mobilizing and unifying factor. In the name of Iran's defence against a foreign invader, much more drastic measures could be taken domestically than would be the case today.
The Green Movement consisted of millions of sentimental young people, mostly aged between 18 to 25, that wanted change. They did not attack public property, they did not burn the flag of Iran, they did not attack police stations, gas stations, fire departments, municipalities or hospitals. It surprises me that you are comparing the Green Movement with the October riots. On the other hand, some factions within the conservative party initially ignited the October riots, only to get surprised by how far it went.
These 40,000-50,000 rioters that you talk about set ablaze over 50 gas stations, and more than 100 banks. Some satellite cities of Tehran were destroyed like an urban war had hit them. Do you know how much time and money should be invested to rebuild those buildings that were burnt down?
Riots cause greater material damage, no doubt. But nonetheless, they do not threaten the system to the same extent as a mass movement (several hundreds of thousands of protesters in Tehran alone) directly backed by almost half the establishment itself.
Just look at the number of political systems overthrown by so-called colored revolutions. Then look at how few, if any, were successfully overthrown by token amounts of rioters setting property ablaze.
And to link this up with the previous point: if the Leader takes extremely radical measures against establishment liberals, and if as a result, said liberals join the rioters... we may then see a combination of "Green Movement" fitna and riots. A recipe for disaster, to be sure.
Iran is no threat to Western countries or the United States.
I disagree. Iran is a major stumbling block to their global designs. Which is why they are concentrating such disproportionate efforts at countering Iran. Their goal is to completely obliterate Iran much like they destroyed Afghanistan, Somalia, Sudan, Iraq, Libya, Syria and Yemen for many generations to come. But they've been faced with failure to this day.
Iran is also a roadblock for Isra"el", constantly forcing Tel Aviv to spend efforts and treasury into containing the ever expanding Resistance Axis. And Isra"el" is the centerpiece of the west.
They are stealing our money and gold while we sit here and do nothing.
Not sure how the west is stealing Iran's money at this time (other than the frozen and stolen funds in the US which date back to the very early days of the Revolution, and which, in other terms, were stolen in the 80's already).
As for gold, this was another "brilliant" achievement of Rohani's administration who had part of Iran's reserves sold (rather than stolen)... however, gold is flowing back in thanks to Iran's oil and gasoline sales to Venezuela.
And while we are making tremendous progress military, so are Turkey and Saudi Arabia. And the Unites States and Israel are making progress too. As I have said it times and times again, only a bold move like going fully nuclear can change the current status quo which is completely against our interests. And Khamenei doesn't seem interested in that.
As explained in my previous post, I don't quite assess the current status quo as being so unfavorable to Iran.
About nukes, remember Iran is not so much at risk of direct military aggression as she is exposed to the threat of engineered "regime" collapse using a combination of propaganda / psy-ops / soft power / cultural aggression, domestic fifth columnists / saboteurs / nofoozis, terrorist attacks, support for exiled opposition and for separatist groups, as well as economic warfare and sanctions in particular.
Just as nukes did not prevent the fall of the USSR, I doubt they'd save Iran from this sort of hybrid warfare all by themselves. Although I'd concede they might present some other, indirect advantages. These however would need to be weighed against the disadvantages they surely harbor too.
Iran survived the immense turmoils of the 80's and came out stronger. The same is happening today.
While in the 80's, Iran benefitted from certain advantages it presently lacks - like the aforementioned early revolutionary fervor, today it is making use of other advantages it then lacked - like its industrial, scientific and military development, or its much more extensive network of allies accross the neighborhood.
There will always be challenges and existential threats, from an Islamic perspective we would argue that this is actually not going to subside until the manifestation of our saviour hazrate Mahdi (ajjil farajahum).
As far as I'm concerned, there are legitimate causes for concern - as always, but no reason for such pessimism, specially when considering the history of the past four decades. Keep the faith and stand strong, as overall Iran is definitely on the right path.