Because he gets to keep his job. That's what a lot of these figthers are doing now. They are forging the actual fight, and seeking to win decisions, and keep their seat at the table.
I've always said that if you change the rules even slightly to stop rewarding the takedown, then half of these types would be gone from the UFC.
You can think Jeff Blatnick for the current takedown rules. he haunts us from beyond the grave./