I would rather wait 5-10 minutes
than:
1. playing with random vs a Team.
2. playing with random who is AFK.
3. playing with random who is so bad, that ist not even funny anymore.
I would prefer the match making was a bit better because it can be frustrating (more so if you are highly ranked match with a low ranked guy vs two high ranked opponents).
However:
1. Teams are not always better. Some players wont play well together in a team or are just not that good.
2. Does happen but the primary reason is because you have to sit in queue for a long time and you don't notice when you finally get a game. Longer queue times might make this worse. Tends to happen very rarely at the top of the ladder.
3. Again this happens the the lower on the ladder you go.
What I would say is that despite all the above problems, if you are good at the game then you will get higher. Everyone has problems with crap match making or people that are not that good.
I play random 2's all the time and get screwed by matchmaking sometimes but so does the opponents as well. If you get a team mate who isn't very good then you should try to help him. Either support his side of the map so you can get control, even if it is only with a few units. Offer him advice and support. Whatever you do dont call him a noob or an idiot and don't tell him what to do. It really irritates me when people do that.