> but that you can't accidentally stumble onto it?

Because even on a platform like reddit, these aren't front-page items nor anything that will casually be brought to attention. If you want to share piece of shit ideology, you have to find piece of shit subs, and they're micro communities.

The reason I think the proximity in that instance helps is users are more likely to interact with users from other popular subs. I've seen racists spring up odd places, get downvoted into oblivion, but will engage in argument. In my view it's more important that they engage with the rest of the population.

You act like it isn't super easy to stumble upon these communities, but all it takes is having your curiosity piqued by an edgy-sounding comment that could be in any /r/all thread. You don't have to seek it out, you just have to be a naturally curious person and you can easily find yourself down a rabbit hole of hate speech filled individuals and communities.