Well, the facts are that Gavin literally did just that; an alternative, hardforked client with a 20 MB block limit, and anyone from the core deve team that didn't like that could watch while he lobbies miners, services and merchants to accept the new client. That was what he said, he has not retracted it, nor confessed the ulterior motive you are affording him. Those are the facts, are they not?
Why do they have to sit back and watch? Can they not lobby those same miners, services, and merchants. Besides, the miners are mostly in control anyway. That's why gavin was so quick to accept the 8mb deal offered by the Chinese miners. He knows who ultimately enforces the code. The blockstream guys don't seam to understand that.