I have never seen any diaspora have more contempt for their own people than Iranians. Thankfully more recent diaspora in the US are both more level-headed and diverse (coming not just from Tehran and a few other major cities but many other places and ethnic groups). I know an Azeri Iranian who was nothing but contempt for the regime (especially after thousands of protesters were murdered) but is horrified by what the US/Israel has been doing.

Diaspora communities are never representative of their home country. This is something I know from my own community, since selection bias leads to a very particular (and privileged) set of people with the means to emigrate, almost universally from a single ethnic group that is less than 11% of the total population. Perhaps you should consider whether the Iranians you know are representative of the Iranian population as a whole.