I think a lot of the opinions on hexbear came from when they first federated. There are the general things like it is a leftist instance, and from what I can tell, they like to shit post. I do recommend lurking for a bit and deciding yourself, they do have their own culture there.
During the initial federation there were a couple of things that lead to their reputation -they have a culture of calling out bad takes, instead of down votes they were comment, so they had a lot of engagement
-with their culture of calling things out, they have a community called the dunk tank, that is usually screenshots of other users with bad takes
-they use a lot of pictures in replies, when first federated these would come out really large, taking up the whole thread. This was unintentional and should be fixed now. A popular one was PPB, which is a picture of pig balls with poop on it, as you can imagine this rubbed some people the wrong way.
They are very harsh against Nazi idealogy and they will dunk on liberal takes, but they are very open and accepting in general other than that. An example of this is I have seen multiple posts from a user who admits he has a drug problem (meth I believe) and in each post I have seen they are treated with respect and as a person, something I don't see very often.
They also get accused of being China and Russian shills, but I have seen a mix of support and criticism. It just depends on what the topic is.
Form your own opinion, check out some posts, they aren't the boogeyman some comments say they are.
Religion, they want to make sure it's a good Christian Gmod server.