I'm probably splitting hairs at this point, but the worst fandoms is more like they're all the worst end of the fandom. I've been around them all, really. Video games, anime, My Little Pony, tabletop gaming, hardcore alt metal, hipsters, Renaissance Fair folks, webcomics, internet reviewing and Youtube personalities, Star Wars, hardcore sci fi, the fucking works. All of these ass ends tend to have people who use their hobbies as a crutch to fill in as a pathetic excuse of a personality, rather than to enjoy life and explore the wonders of world, and they all happen to share the same personality of being posturing losers who have never been assed to use any part of their brain beyond their reptilian portion as the neanderthal shit playing assholes they are.
If you want some in depth perspective from me on this though:
In general, fanwhores enjoy saying they're "openminded" when they really are not. Seriously, this is either done out of fearing what people think of them more than actual worry of character and personal development. Fanwhores are infact extremely narcissistic and closeminded.
Fanwhores also these days don't have a bigger vocabulary or as aformentioned, an actual open mind. One word they like to use is "weird", because they are usually the cause of why art programs get cancelled from schools. They also have never had any interest in the world outside or are that jaded by people who they wuss out in taking retribution against, and they tend to be closet local trash. TL;DR they don't bother to continue learning after general education on their own, and even then, they tend to be unwise jackasses who think material possessions excuse them from personal responsibility.
Anime: I've always encountered hipster faggots who pride themselves on shit like "taste" and enjoy praising themselves for fanwhoring out the right way..... when they don't even realize that they're the same foreign fans who are fatheaded know nothing know it all limpdicks who think the entire world revolves around them and the world they grew up in, and so does the entertainment. The ass end of anime fandom is also mostly plagued by whores who think anime can only can be made in Japan because for some, utterly inexplicable reason, only and only Japan can magically create animation. This lack of being proactive, constructive, and artistically motivated has long been the reason why anime fans out anywhere else are a joke these days.
Video Games: Gamer tards you can recognize today as mentally ill trans male to females. This is because they were once smarmy know it alls who worshiped atheism while touting their games they like as all important, until being a complete sperg in real life likely caused them to look like complete faggots, probably sperging out on ignorant shit.
Cartoons: These guys always tend to be jealous of anime and think the world needs to know how much they don't like it, because anime showed the world that it didn't have to suck the dick of censors and be baby shows and cut and dry capeshit. I know I cling to the past, but anime proved itself. Cartoons had the ball in their court on CN at the same time, but fuck did they drop it and let it get run the fuck over.
My Little Pony: I like how Null forgot about this today when he sperged on about how much he doesn't like anime. We all can go on about if "anime is actually really anatomically accurate and expresses subconscious desires to fuck kids that the Jews are trying to exploit", but ponyfuckers are all male, and they tend to be more embarrassing because they're cartoon bestiality enthusiasts for a show that's literally aimed for children. Ponyfuckers also fall into cartoon spergs, but they gain their own category because they wanted to stand out that much.
Renaissance Fair goers/"realistic reinactment" enthusiasts: Dumbasses who are more interested in feeling powerful than actually studying history, and not getting the human reason why everyone back then would kill for what we have today in terms of quality of life. They also tend to be armchair experts who don't do shit but use the internet to feel better and give everyone else who attends and arranges Renaissance Fairs a bad name.
I am I Love Beef. I hate everyone. You'll see me later in the future on this thread.