Jeez, it's not like this site is important enough to worry about post counts. What does 20,000 posts on the escapist tell us?, it tells us that the person likes the escapist and has posted a lot. It doesn't afford anyone a more valuable opinion, except in the eyes of the auto-retort douchebags that assume they know better because of some digits at the side of their screen.
I'm a moderator on a game dev forum, and we removed the post count display because it just made people spam the hell out of the forum, like some post-pubescent pissing contest. Really nobody minds that their post count isn't displayed, they can check it themselves.
Post count here is pointless, as pointless as having a badge to signify that once a week you spend 2 minutes answering a quiz. But there's not much else you can do really, everything they could add would be abused somehow. It might be interesting to see what would happen if it was hidden for a week or so - then people would have to do things like come up with interesting topics, or help people out more, to get themeselves better known.