This is probably obvious to anyone who has played DG. The matchup service will say "8 players waiting", then promptly load up with 1 player and all AI on one team and all human on other team.
I, like everyone else I've seen, promptly drops. People tell me: "custom game!". I know that is AN answer, but I generally just jump on, want a random game or two and then that's it. Sitting in a custom game forever just to get it going isn't appealing most of the time.
I'd rather just NOT get a game, than go through 5 "Oh, 3 AI on my team... quit" in a row. Just have it say "Not enough players, go pound dirt" and I'll be happier than the way it is now.
On a side note, why does DG have such a small following? Company of Heroes has more people in it and it's stale, out of money, and just plain imbalanced as hell after several years. DG is great, fairly balanced with focus on teamwork, and lots of ways to win the map. Graphics and music are top notch.