It's because a lot of the people hate the regime and want it gone. You can see that in activist spaces like the /r/NewIran subreddit or on X from accounts like https://x.com/__Injaneb96 that yes, they do very much welcome US intervention.

Here's a video from a townhall in my parent's congressional district where some Iranian-Americans speak up on the war: https://old.reddit.com/r/NewIran/comments/1rbdxzb/democrat_c...

It's quite similar to Ukrainians complaining about Putin. "My country sucks, come save me" is always a trap, because if you attempt to come "save" them you just get called a warmonger.