Excessive fanservice, mostly. Like it's completely overwhelmed the genre when the isekaied protag is male. There's only a handful of stories I can name that don't have it. Like, I can handle an OP protag so long as it's done well (re: that one time i got reincarnated as slime). I can even handle a little fanservice. But when the entire plot is just "man died and now he gets laid constantly, and there's a little plot in the background", it's just beyond annoying. And there's always a whole harem. It's completely saturated to the point where it's required. It's especially annoying when the plot isn't even good enough to overlook it. I'm tired. There's so much potential for in depth stories about what it means to be separated from your home to save other people in another unfamiliar world where you have to search for the things that stay constant, but instead it's all just... lacking, I guess. Instead it just turns into "who will the male protag conquer next?" I don't think I'd mind it if there were other options to read, but there aren't, really. You have to hunt for the unpopular ones.
