I have about 80 friends in the game, but most the time 0 to 2 are online when I want to play, including those who are idle or already in a game. It took me three days to get a friend to join my team when I was trying to do a weekly achievement with a party.
I do not complain about random teammates, I complain about the AI, which is pretty useless. At the very least they should increase the AI skill level, because now it looks like a two-year-old is attempting to control it, only to bunny hop off the map having contributed nothing.
Another suggestion would be to allow players queue for specific maps, or create a favourites list which could 'weight' the map selection options. People who love all the maps can still choose to queue for all.