People say the sonic fandom, the Thomas fandom(i guess?), and of course the my little pony fandom is hated not because of the members, it's because of how big the fandom is and how much fans can connect with each other, the reason popular shows are hated and hate stamps are created it because of simple jealousy.
I guess the bigger the fandom is, the more people know about it, and thus the more haters there are against it. There are haters against everything, if a fandom gets large it just means there are more haters, but that doesn't mean that, in proportion to it's size, they are hated more.
I can answer for why the Sonic Fandom is widely hated. It's mostly people who take the OC/Sonic Fan Character thing too far and a lot of new gen(young kids) fans think they know everything about Sonic. They cast down all those who have played Sonic since his early days, saying that they are being posers. I am one who has played Sonic long before a lot of these sniveling little brats have. I left the fandom because of those kind of idiots and I don't wish throw those kinda people on anyone. The Sonic Fanbase makes practically every other fandom look sane and normal compared.
That actually has a fandom? I mean, it's a cute little show and all, but an actual honest-to-god FANDOM?
Eh, jealousy... I guess you could also say that when you don't like something, but this something has a huge fandom, it's pretty easy to get annoyed with this something being quite literally everywhere all of a sudden. And while some people just roll their eyes and move on, some people group together, spending all their time and energy dealing with the very thing they hate because, apparently, they don't have anything better to do. Go figure.
Thomas the Tank Engine falls into the category of ironic fandom. I'm 90% sure that no one that's in the fandom genuinely enjoys the show, given they're old enough to know what fandoms are. And, given that every fan I know is an architect, It's not exactly the biggest surprise.
