Actually, this is exactly wrong. Think about how a show comes into existence...the planning, testing, piloting, etc. You're looking at it through a post show successful launch. Now back up to prior to shows launching and how they come about. You will have many fewer new shows, much less of the riskier ones because there will no incentive to create them.
I don't dispute that there might be fewer new shows, but I don't see that as a problem. Good shows will find a way to get on the air. Instead of true a la carte I would also be in favor of choosing channels based on programmers or more sub-packages. i.e. If I want one ESPN channel I must buy all of them. If I want HGTV I must buy all the Scripps networks. Even this would make more sense then what exists today. But it doesn't make sense that everyone must pay for ESPN and their exorbitant fees if they have zero interest in sports.