Oh I've seen it - some people receiving downvotes between replying to me and me seeing their content, which I thought was odd so I checked out their post history and literally everything had been downvoted. Obviously that's a sort of troll attack (except one case where the person said that they were doing it to themselves, so as to imprint upon themselves how worthless those scores really are). Admins can see such and ban accounts doing it, but some instances allow automated signups so there can be an unlimited number of accounts that would need banning though, if someone were determined enough to keep making new ones.

But that's not what drove my irl friends away - that was content that e.g. made fun of the Western world & society, and which they considered "extremist", and did not want to see so they left. And as others have noted, if you remove politics and Linux, then other than Star Trek what else do we even have here?

A community, that's what. But that takes awhile to see, yet they were already gone.