This is a good summary post I think. One thing I've noticed about the anti community is that most of them aren't truly engaged in any communities/series. They seem to focus on the current "new big thing" and once the hype dies down, they don't stick around long. In both of my most recent fandoms, the antis only stuck around for the first few months, right when the series were at their peak in activity. I'm a fic writer, so I tend to stick around much longer. Now I only occasionally see the random post at most once a month about something negative and it's normally a legit complaint within the community itself, not an anti post.

So I guess what I'm getting at is that antis are fans of the anti community before anything else. They seem to focus their attacks on the most popular communities where they will get the most attention without actually engaging/producing content/consuming content in them.