I think it's useless information that leads to padding and an ill-conceived sense of accomplishment. It lends itself to members posting instead of reading. Someone will see a topic or question in the first post and they tend to type a reply without reading the thread to see if it's been covered. There's other reasons for this, of course, but displaying a post count lends itself to this type of behavior.
Say someone has 10,000 posts. What does that tell you? Nothing really. They might have received all of those posts guessing numbers in a contest. Meanwhile, someone with 100 posts might have used all of those posts to educate and help other vapors. Which person would you rather take advice from? Not to mention, there's areas of the forum dedicated to helping folks (i.e. Co-Ops) where posts don't even count.
IMO, it's a useless unit of measure, and I'd rather value a post based on it's own merits rather than a number under someone's name (for the record, I feel mostly the same way about join date. Length of time on the forum does not necessarily equate to knowledge on the subject).
