I haven't interacted with a huge part of the fanbase, but the worst I've personally encountered are the "Wow, you made a very simple thing that happens to be good? You should be replacing Sonic Team" people.
I'm really into the modding community, and I can't think of many good mods I've seen without anyone attached to it saying "wow, you're so much better at this than SEGA. They should hire you", even with incredibly simple stuff like adding a few enemies to Unleashed day stages or speeding bosses in Forces.
I know that it's not nearly as toxic as any of the people you mentioned, but I have never met any of those, so I can't personally say anything worthwhile about it.