[toast0]

Games with peer to peer networking also need (or want) to establish connectivity between candidate matches. No sense matching two players that are behind NATs that won't be able to communicate.

It does probably make sense to wait a limited time for a better match though; better to wait a minute for a better match than to start right away and play many minutes of a terrible match. The wait time might vary based on the quality of the match... but you don't want to have someone stuck waiting if they keep getting matched, but the partner finds a better match.