To pick an example that won't upset any people (ok, not many people), if someone shows up in Common Lisp threads on HN with the sort of chauvinism that destroyed comp.lang.lisp, that's toxic and I'm going to moderate even if I share their views about Lisp. This is a real example btw. I found https://news.ycombinator.com/item?id=9813527, but there have been a bunch of cases.
Can you give an example because you make no sense or you are stating something obvious, yeah communities do not agree with toxic things because they are bad.
The toxic meaning is clear in the context of each community, if you don't agree then don't join, if you want to join follow the rules, if you just want to join and not follow the rules and you want to create harm then you are toxic.
I think there's some room for common sense as to what communities should be given a platform and which shouldn't, for example I don't tihnk /r/coontown should be given a platform in western society which is overwhelmingly anti-racist. But the moment you start banning communities based on criteria that go beyond basic common sense of your society, especially of you do so based on vague and ill-defined rules, you're no longer being a neutral platform. If Reddit wants to be a community as such that's fine, but from my perspective that's explicitly not their branding, and it doesn't seem to be the opinon of Reddit users as agood whole either.
Not the full reddit platform, it is a private thing and a business, if keeping toxic sub-reddits on would make them money and good PR then they would keep them , it was a business decision and if it is legal then it is nothing you can do then move your community elsewhere.
I also don't like when business ban perfectly legal things like adult content but what can you do? Make a law forcing business and private people host things that they don't want, if you had a forum and someone would spam it with disgusting images don't you want the freedom to remove that? Reddit is not a monopoly, we have forums and they even work better for some content type