not a fandom hate, but the sterotypical hate towards Pokemon Ruby and Sapphire. yes, retroactively they may have been a let down in comparison to the Fandom's common fondness of GSC. however even after drawing back from using fully animated sprites, 8bit noises into using soundfonts and upgrading color was a start, however it felt like a slight reboot of the franchise since so few old Pokemon appeared, and this was just after Pokemon started to drift down in popularity in the west. eventually you'd have to buy 3 lots of games to get a lot of pokemon, maybe there's a slight bit of crossing over with Emerald.
It's a single generation in the franchise, i get it. but traditionally Pokemon is one of those franchises that looks more archaic the further you look back the generations as you play more modern generations. it isn't something easy like Mario or Zelda can do. stuff like Pokemon Diamond and Pearl's pokemon selection may be a slight justification as hate, but it did bring back individual days of the week, internet and pseudo-3D graphics, it does lack in the story department to a degree however that and the Pokemon issue was neatened up with Platinum. the issue with the whole looking backwards thing is that GSC was pretty refined and made as much use as they can on the aging gameboy, even if they had to snip a few things like Viridian Forest and the Seafoam Islands which were eventually restored in HGSS along with music and a bunch of other things.
Another fandom? probably getting too close to a flame here. but Touhou. a franchise that's made out to be much more massive than its supposed to be, it has lots of fan art, doujinshi, music videos, flash cartoons and so on, it proliferates countless forums and possibly crosses over fandoms. but as a newer person, im only aware of a few characters, you'd probably have to go through lots of hurdles into actually playing the games themselves only to die a couple of stages into normal mode. trying to figure out the plot? good luck, the creator put a moratorium on talking about full games' plots in detail; so databases puts the plot into the character profiles themselves which would be hard considering how far a part character links were. even worse, this is a videogame series not a four-thousand-page flash cartoon series, it should be easy to get into....but it just isn't. you'd probably get looked down and would likely not get the full story/ending if you played on easier modes to boot.