Well, I know Gabe isn't stupid. But he could do so amazing things and he doesn't. One of them, like you said, it was the production of HL3. I hope they release in a near future.
The second is something that the American PSN have: If you clear a 100% game, you receive 25$ for being a good gamer. Steam has more money than PlayStation, they could put some strategy in the company for benefit us, gamers.
It's just an opinion but I think you're right.
I loved L4D 1 and 2. Hope the next could be better!