When was the last time we said the Internet Protocol, routers and hubs worldwide, need "sex workers and black groups". Sounds like nonsense, because it's just a platform, a technology.
Well this is how social networks must also be. And a social network should allow multiple communities to form and each community to moderate itself. There's no other viable way I can think of.
The platform should only be invoked for dire circumstances when the platform integrity is being violated itself.