In a highly controlled environment like a football stadium where access is limited by things like ticketing or wrist bands and ID checks I would see nothing but upside. The ouside environmental issues like pre-game tailgating and/or showing up to the game already drunk are the impact issues that demand change.
Deny stadium access to an already drunk fan or deny him more beer an you will find out what your refreshment policy is made of. Not sure if this has happened at MP/MF, but it should.