I actually really like the openness of the stats on this site. While I completely agree that stats aren't everything, they do factor in. Schools wouldn't make you take the gmat or list your gpa if they weren't relevant to your candidacy.
I think stats have a usefulness, and I personally think that more people should be open about them. I think there are many people that love seeing other people's stats, and yet they're paranoid to post their own. I would actually prefer that everyone list their stats (in the 2010 profiles thread).
As far as a privacy issue goes with posting stats, I don't really see a problem with it. I'm not going to post anything on here that would bad-mouth any school. It's similar to making sure that you don't have objectionable content on facebook. The reality is that the school has access to most of the information I'd post on here anyway. The other reality is that for people applying to multiple schools, only one will be your favorite, but you'd like to get into every school which you applied. I think adcoms know you've applied to multiple schools, and that whichever school they work for may not be your dream choice. I also don't know how much stalking a member of an admissions committee would do. They see a lot of applications and don't have a lot of time to make decisions (it only feels like a lot of time).
As far as the Kellogg thread goes, i think that it's completely out of hand (albeit, I'm not sure it's spamming either). If people just posted their stats in the right place, you'd have a very nice reference for everyone who cared to look.