by Maugh » Thu Mar 08, 2012 1:57 pm
Two reasons. First, it came that way automatically, and it is more difficult to install a custom registration process than it is to leave it the way it is, and second, there is actually very, very minimal demand for legitimate new users, but a significant demand from foreign users (bots). Manually accepting/rejecting is annoying, and a good captcha prevents that.
"Use the best: Linux for servers, Mac for graphics, Windows for Solitaire."