Simple. Just let people choose the map they want to play in rated lobbies (or give them unlimited bans).How can you expect the devs to create a good mm if there is active dodging happening and it is undermining the system?
It's a damn video game. Most people play for fun. They don't need a gaming ethics lecture about how they should play map X and Y but not Z.
Also I don't see why it is not possible to have a system where once a match is found, you are given the option to continue or requeue, and if your opponent requeues - you get a priority in finding a new match (instead of the opponent getting punished).