Well for one, their post count will increase, and this is probably not a legitimate reason. To sum it for you...it's the same reason that when you delete a member their post don't get deleted either. Why? because if someone deletes their posts, then the forum will become very confusing. Example: if someone deleted their post, it's like deleting a part of a conversation, it won't make any sense to the other people that read that thread. And edit and deleting of posts is slightly different, if someone edits their posts and the conversation doesn't make any sense, then one can conclude that he/she edited their post, its common sense. It's not a big deal allowing people to delete their posts...if they really want to they could edit their posts, but at least other people would see why the conversation doesn't make sense. And that's my point to this.
You're not going to allow deleting posts? I think it's a must for any forum. There's only one forum I can think of that doesn't allow it and then you get posts that say delete this or something because people can't delete and they changed their minds about posting. Seriously it's not going to create any confuision, if anything it prevents confusion, because people might post something inappropriate or off topic and realize it right after their post shows up, and they can just go back and delete it.
I see you guys are a little torn on this.
I've used the delete function myself on several forums, so I'm going to keep it on for now, since I thnink it wont be a huge problem.
As far as I know, as soon as someone replies to your message you can no longer delete it.
So as a matter of convinience its going to stay on for now. Thats enough on that topic.