Fine, MKO is a bad choice for Iran and Iranians. I agree with you on that, and have never advocated MKO as an viable alternative.
And the mullahs and their klicks are a Shia minority in Iran who rule over an oppressed majority. A small, albeit a well armed one just like Saddam, the Ghadafis and Assads, who have build a private militia to keep the rest of the population in check! Spend billions of dollars in Syria, Yemen, Iraq, and Lebanon in spite of acute needs at home. A corrupt and indifferent political class whose prime objective is regime survival.
You have a country that will again face the most draconian economic and political sanctions ever imposed on a country. It was the very same sanctions that brought IRI to the negotiating table to begin with, and to her knees, whether you like to hear that or not. And TBH, it really doesn't matter what the EU, Russia, or China say about the US's move. They will all fall in line as soon as their economic interests in the US are threatened. We have seen this play out over and over again.
Iran is an ethnic melting pot. How hard do you think is to light a fire under the disenfranchised and disillusioned people? I am betting perhaps in the range of $25-50 billion, a rounding error when it comes to US.