To OP: A large percentage of normies generally aren't all that deep into to the anime/manga community, other than just watching surface level stuff. It also gives incentive for the fringe groups and minorities to get into it as people posting within the confines of these communities are less likely to judge others for their "so called differences".
So these anime and gaming communities work as "escapism places" for a lot of these folks (including uh...vs communities ya)