Because Erdogan's extremist, terrorist and fascistic policies is so exposed that openly defending him, makes one to be ridiculed by any sane person outside of Turkey.
First of all you are not a Turk, nor you know Turkish....and being a Farsi who is living in America, you have absolutely have no idea about the thoughts o the Turkish people....
Turkey's president is "extremist, terrorist and fascistic" not more than you...
Even these Erdoganists know this fact.
Why don't you ask this question to people who support Erdoğan, instead of talking for them ? There are plentty of them in Turkish section.
Second point is about the strict censorship of Turkey that they don't dare to say anything against Erdogan,
Another lie.. there are tons of anti-government media..zaman, hürriyet, sözcü are the just main-stream ones.
since it's considered as a big crime with severe punishments to speak against the president.
Another lie.. it's not speaking against the president but insulting/swearing president....and it's nothing new. Insulting both Atatürk and President has been forbidden by the ages....Severe punishment is 1-3 years imprisonment...but...you need to be convicted for multiple times if you are going to sentenced to prison
Although, as you said, we all know that Erdogan is supporting ISIS, and many other of such groups to promote his new-Ottomanism strategy.
That's some baseless allegations that Turkey is supporting ISIS...we heard this over 2 years yet not granted a single proof. Even not a Turkish made weapon or ammunation in the hands of ISIS.
Also, as a Farsi...you can't talk in the name of Turks.