Fandom in general is an excessively toxic space, and the bigger the franchise the more toxic people you will encounter. These people do not comprise the majority of the fanbase, and are simply a vocal minority, but their presence is still felt on the Internet especially wherever you go online. There are several kinds of toxic people on the Internet you will inevitably encounter, which include the following:
- Elitists. People who are so incredibly full of themselves that they assert what they like as better than everything else and will actively put down and insult other people for doing things differently from them (case in point: dub vs sub elitists in anime). What you're describing seems to be an extension of this, and these people are often the most toxic people in arguments and discourse.
- People who hate a thing so much that they will actively put others down for liking something they don't, in many cases going as far as to threaten them or wish harm on them. Even going as far as to try to convince others they are wrong for being excited about a certain upcoming game and attack them.
- People who cannot take criticism about the stuff they like, because they make what they like their whole identity to the point where they take any criticism against what they like personally and get exceptionally defensive about it.
There are probably other kinds of people who start shit and drama, but in general there are many people out there who want to start drama all the time on the internet and are in general there to stir conflict amongst people who are in a "fanbase" of a franchise.
The key thing is to not let this stuff get to you and in general, I find that the most ideal thing to do is to minimize your interaction with fandom at large and to enjoy things on your own terms. It's fine to be critical of what you like too, but don't get too involved with fandom discourse and do what
you enjoy, and most of all, form your own opinions on things without letting a hive mind or other people influence you. Best of all, it's much better to stick with a close and smaller circle of friends who share your interests rather than engaging with the fandom at large most of the time, regardless of what kind of media franchise you enjoy.