Just posting isn't the same as just threading, in my opinion. What posting does is give people a chance to approach you for CR. So if you do that every month, I don't really care about your reasons. Not everyone has a ton of spare time. Some characters aren't very social. You know?

Of course, someone who always posts and gets tagged and doesn't reply to ANYONE deserves to be complained about, but I honestly haven't seen anyone who does that on a regular basis. I think the act of posting itself should be motivation enough to tag back.