While it's certainly pleasurable to think of not having to visually wind your way through a forest of arms holding phones at concerts, what if a bomb went off or someone became ill or a babysitter needed to get through?
If there's money in the budget for furnishing and managing anti-phone pouches, there's money in the budget for ensuring that phones are placed on silent and vibrate, or ejecting phone photographers/texters who ignore signage prohibiting it during the performance.
Foo Fighters Generate Concert Photo Controversy