Sounds like you aren't fan of those subreddits but should they be shut down if they are not violating the site rules? The fact is that those subs are heavily moderated. If they weren't they'd be the first to go.
The point is that the rules should be changed to disallow those sorts of subreddits. Let those users go somewhere else; reddit has no responsibility to society to host them.
I'm fine with these subreddits, aslong as they're properly moderated and not calling for violence or start brigading other subreddits. When the whole Jessica Price controversy happend there was a lot of new users on r/Guildwars2 that never posted there before or even played the game. I don't agree with them and think they're vile, but aslong as they don't break sitewide rules I'm ok with them.