i think in general any subject where people are actively making others behave in antisocial or toxic ways are kinda :\
PUAs, MRAs, unschoolers, CF-hardcore, fat activism, otherkin and tumblr asexuals all sort of fall under this umbrella.
there's something charming about the madness of monkeymoms or the delusions of failed kickstarters, something endearing about terrible fanfiction and weird fetishes.
but i think it's because ultimately those people do harm only to themselves (or their monkeys i guess) and you can sort of chuckle at it.
but when people are actively working to deconstruct basic necessary societal elements (like respect of women, trying to stay mildly healthy, trying to function like a normal human, looking down on others for the basic desire to reproduce, actively attempting to raise a child who can't behave well in a structured social setting etc) there's a line that gets toed across where while you can laugh, you also really really want these people to stop.
because while bad fanfiction might make you cringe a little at someone's lack of writing ability, it's not going to leak into the real world and have actual ramifications if it does. well, unless you count twilight. but even twilight doesn't fuck shit up like an unschooler can fuck up a classroom (or a kid) or a pua/mra can fuck up a woman's life via abuse or pushing for weird regulations.
the rediculists manage to make even the abhorant topics really funny, though, which is part of why i like the podcast.