atheism's foundations are pretty simple and not really enough alone to form any unified identity around.

They say the same thing about Antifa and BLM too.

Rather those behaviours being associated with atheism are the more the result of successful coopting and gatekeeping many years ago of the atheist-as-an-identity

That's what every feminist, Liberal, Leftist and every other group we criticize says when called out too.

Atheism doesn't get to be an exception just because people here are personally part of the group.