There is another possibility. It's possible there are select posters who feel the childish, and mildly embarrassing need to actually bring up another poster in a negative light in a situation in which said poster isn't even involved.
For example, it would be a bit silly and puerile to bring up a poster in order to bash him when the poster being brought up hasn't even appeared in the thread one was posting in. It's also a bit creepy. I have never personally thought about individual posters throughout the day, wondering what they are up to, wondering when I can bring their name up to score a few comedy points with the other anonymous posters I am posting with.
Then again, I'm all for having fun at each others expense. Also then again, I don't really care either way, just seems a bit odd.