It's mostly fine to shit on atheists as a bit, the same way there was a trend on chapo to make fun of Italians - although of course like anything in that vein it's important to be careful that you aren't making the space legitimately unwelcome to those people and attracting bigots not in on the joke.

With atheism in particular it's kind of the default of most socialist thinking - materialism, natch, though that isn't to say that religious socialist movements don't exist and haven't done a lot of good - so when people make fun of " "atheism" ", they're really making fun of a pretty small subset of atheist dude bros that make it their whole identity.

As for why they're targets, it's because of the way that a ton of what used to be the quote-unquote "leaders" of the atheist movement a decade ago, Richard Dawkins and such, went on a massive right wing tangent against muslims, trans people, etc in the name of "western civilization" - and as an atheist myself (tips fedora) I say we bully any losers who actually buy into that as much as humanly possible.

Anyone making the "I believe in logic and reason, which is why I'm going to team up with the reactionary right to harass brown people" argument deserves to be dropkicked into the center of the sun.