They "love" the aesthetics of them and not much more, which is why when you see a lucky star fan who has seen the show and one who hasn't, they act pretty much the same. The barrier of entry for 'getting into it' is basically just saving images/gifs, and since the show is already popular it makes sense that they'd become fixated on what they're frequently exposed to, rather than something more obscure. It'd be more accurate to say they love individual characters from these shows rather than anything as a whole. And obviously they're predisposed to obsess over real womenme girls like this in the first place because they're all incels, lol. It's not really anything to do with their political beliefs, they have the same reasons for "loving" these things as real women do. Same reason things like touhou are popular.