What am I missing? What's wrong with input switching being made at the OS level?
But not all. So, clearly it doesn't have to be below the OS level. I agree it needs to be quick, responsive and reliable, but that doesn't preclude it from being implemented in the OS.
Input switching on my TV doesn't even cross the Doherty threshold, or at least not in any way that I notice. And believe me, I get as irritated as anyone with laggy TV menus - which is one reason I refuse to buy Samsung at this point.