I can’t speak for the people that made the community but I don’t think that places like this are necessarily made by vegans for vegans as you describe. Personally I can attest that it’s just extremely frustrating to be made to feel like an out group in the ONE community where you shouldn’t be made to feel like that. I personally welcome nonvegans to participate in discussion so long as they come with the understanding that they are a guest in our community and should respect the community as such which does include taking care to not come across as tone deaf. I’m not religious and in fact actively oppose religion but if I found myself at a church for whatever reason I’m not going to go in there and start a bunch of arguments and whatnot. I would be respectful because I understand that going to their place of worship and causing a commotion is uncalled for and doesn’t benefit anyone. To be clear, I’m not trying to say that veganism is a religion because it is not and it is not viewed in the same way as religion is by its followers. I am merely using the analogy to illustrate how you should act when going into a community that you are not a part of.