The fact that some boogiemen are not as terrible as portrayed, or that we shouldn't put too much effort to go after them, does not imply that all boogiemen are actually nice.
There's also the fact that more often than not, they act based on internal power plays and national interests of its own, and not for some "greater good".
There's also the fact that they have fucked up tons of countries with their interventions -- 4 countries in the last 20 years ago, turning relatively stable regimes into hell-holes of civil war, mayhem, and terrorism.
Not to go into how they have been historically worse than the boogiemen they complain about (from funding dictators, to directly invading countries, toppling democratically elected leaders, and so on).
I think that goes without saying. But after fighting ideological / proxy wars against communism, "terrorism" and "hell, just because" I think we need a little more support.
Here we have a long-standing soft war against a country and/or people for whom Western meddling has demonstrably affected their life for the worse. Every time they do anything acting in their own sovereign interest we peg it as evil and impose some wrist-slapping or worse.
I don't for one second believe that the leadership of Iran is "good." Nor do I believe they're inherently evil. We refuse to concede any responsibility in the fate of their land over the last 100 years, continue to box them in and it seems more and more apparent we're keeping them on the hotplate in case we need a new war.
I have a pretty skeptical view of lower-case-l libertarians, most of whom are just using it as a veneer over some otherwise lockstep partisan affiliation. But one thing I've found very encouraging is that movement's general cynicism toward continued world power interventionism.