pre-loss quitters

If the lobby was better, and servers had the choice to enable such a feature, I guess it could work. For example if you see people in your team pick classes that will make the game hopeless you quit before it starts and it doesn't count as leaver.

People leave or join all the time during a round, it affects the balance a lot and there's zero feeling of playing within a team. When it lasts only 17 minutes it shouldn't be so exceptionnal to have the same people in the teams from start to end.

I'm not really expert in DotA likes, but I think a lobby in the spirit of HoN's could work pretty well in MNC.

I honestly don't see any benefit in trying to force somebody to play a match he doesn't want to. He will just sit it out in the spawnroom or hide in some corner. There is nothing you can do to force somebody to fight for your team.

I'd rather have the chance to get somebody who is good in the last 5 minutes than to have somebody taunting in the spawn for the rest of the match.

If it's an option and not forced on all servers nothing would force them to join such a server.

The benefits of such a system? It's not an instant benefit, but a long term one: if there's no other way to play a decent match than finding 11 other people you know to play with, you will loose most of the players with a somewhat decent competitive spirit but don't want to get involved in a team, while keeping mostly the trash players, so even if the game is good the community will make the gaming experience bad, and the result will be the same than if the game was bad.