I didn't leave - SC just crashed on me
I made a bomb push specifically in case baja may need some help early on (he did great against the ff rush, btw), because he had the worst position of us all. I use them as an early-mid counter in single-player sometimes, but they work much better in team games.
As for the AI's skill...well, something was clearly going wrong yesterday. We played 2 comp-stomp games before that 3v3 match, and the AI wasn't even weak - it was outright dumb! In the 3v3 it at least didn't stall or something, but it wasn't a real challenge. The single player matches I had were much more challenging, but I have no idea where could the difference come from.