This just isn't reality in any mainstream sense, though. Putting aside the policy of actual governments or the stances of mainstream media in the west (certainly not much notable apologism or favouritism for Iran in either) and sticking to general online anti-US/Iran and other authoritarian regime hypocrisy, you only need a cursory glance through social media or large online discussion boards ( like reddit's biggest political subs) to see that there is in fact a great deal of condemnation and disdain for the Iranian and other authoritarian governments from all sorts of political viewpoints. This had been the case over the entire social media era. They're all full of talk right now about coming down hard on them, making an example, or incoherent takes about appeasement in the middle-east not working (with obligatory WW2 references)...some of the "needs a reaction" talk is moderate in scope, but there's also plenty of overt 2000s Bush era warmongering. The latter certainly outweighs leftist/liberal apologism for Iran by a considerable margin from what i can see.
These far-left apologists that only criticise the usa/west then automatically default to their opponent in any issue being a justified good-guy are a powerless, irrelevant tiny minority; it's largely an online thing too, compared to the real damage the far more mainstream public acceptance of populist right-wing to outright far-right views is causing. It's not the 1960s-70s when there were genuine far-left militant organisations or parties with some power causing trouble in Western countries (Red Army Faction, the Years of Lead and strong communist support in Italy, etc.), while at the same time genuinely believing a lot of the partially-to-entirely true stories of authoritarian brutality coming out of communist countries was all propaganda.
