Originally Posted by
Okuu
Cute. Which one is you and which one is me? :3
Basically, Valve doesn't want a public MMR but Dotabuff released one.
Before the rating system had even finished rolling out, Valve added an option so third-party sites can't read your match history (and thus determine your rating) and since the rating is only accurate if everyone has one, the rating system broke completely. Dotabuff then threatened to shut down and put a notice on their front page asking people to mail Gaben to beg him to stop. They didn't shut down anyway, buncha drama queens.