I can't speak of all diaspora members everywhere, but some of them basically just have a blood feud with the country. They don't want to go there, but the government hurt their ancestors so now it's part of their life's mission to see that government fall, and none of the civilians suffering are real to them because at least most of the country isn't real to them (except, depending on the person and country, one or two places they may have visited at some point). It's made all the better in the case of a country like Iran by the fact that the country they have a blood feud with is the country of "their" people (as opposed to like a Ukrainian's blood feud with Russia), so they can just call you racist if you're not the right ethnicity and tell them that what they're saying is fucked up.

I've known a couple of people who don't know staggeringly basic information about the country they purport to speak for -- things that literally over 99.9% of the people on this board know -- and have spent basically all their life in America and in some cases don't even have a conversational level of "their people's" language (not for lack of documentation or even American speakers!) who just fucking love to do this shit. It's odious, but their fellow liberals eat it up.