Well, all fandoms have a toxic element to them it’s when that toxicity infects the larger populous, or becomes the majority voice, that the problems start. What elements are toxic vary from fandom-to-fandom.

For example: Overwatch is a mess because it attracted, to put it in the simplest terms, SJW Casuals. They’re incredibly militant that they’re views are the only right ones and that they should be catered absolutely. The OW team has been completely lackluster in adding in content for people interested in the game’s lore (which is just a cheap frosting they slathered over the game to attract said casuals).

Add those two things together and you get the OW fandom.

For another example Fire Emblem: I actually FE’s fandom is worse then OW because it’s basically like 3 different factions. You have the elitist pricks who played the old games and think the direction the new games are going is killing the games despite the opposite being true. The SJW Casuals like OW, and the new wave of people who came that aren’t apart of either group. And they’re just fighting all the time. Oft screaming into the void how each other is the worst.

While “elitists” has become the boogeyman term in the fandom in recent times lets be clear. They’re all awful (ok, the new people who just want to enjoy FE aren’t completely awful but they’re not exempt either).