People like things. That's better than not liking things. Unless that thing has some type of moral charge (for instance, some people like stealing things – that's wrong, duh) we should probably not ridicule them for it.
This seems like a necessary follow-up to my discussion of Avatar and Megafans. Obviously, wanting to be a Na'vi is a too much, and it's more psychologically healthy to have aspirations that are, ya know, possible. But I was in no way dismissing someone who really likes Twilight.
There are a lot of things to enjoy, and you don't need to personally approve of all of them. When people talk about "toxic fandom", they typically refer to several, vanishingly rare, rude or weird people in an extremely large group. But we know every large enough group without the ability to eject bad actors has bad actors. So why do we imagine those people are meaningfully representative? I'm not even sure we do – I'm pretty sure people just want to inter-group rank against e.g. fans of Rick and Morty. They're bad, and I'm not bad. Like sports teams – the team you like is defined by their relationship with the fandoms of other teams.
This is, in 2019, substantially more pathetic than e.g. the adult men who enjoy My Little Pony, the fandom most reliably portrayed as pathetic I am aware of. Truthfully, I have no idea how pathetic it is – on a dare, I tried watching it, and literally couldn't stand it. Perhaps it's more well-adjusted, and appropriate for adults to enjoy, than it appears in the first few minutes of the first episode.
But the worst that enjoying My Little Pony could do is delight someone. Trying to tear people down because they like something you don't, in a desperate attempt to make a dense tribal world in a fractal of complicated cultural mess, that has no upside and a casual cruelty to it. There are tens of thousands of fairly successful YouTube channels, for instance – you cannot possibly have an opinion on all of them, you cannot have judged them good or bad. Give up on that project – even if you could rein in excesses or ill judgment you simply wouldn't have the time.
All our effort in etiquette needs to be devoted to actually being kinder to each other, and really only cracking the whip of social condemnation when people hurt each other. To see those tools turned to the strange borderline-infinite cultural horseraces of the modern day is just sad. Etiquette is too important and rare to waste on harmless strangers.