Playing Devil's advocate, it would look pretty dumb if one of these guys swallowed and choked to death on a straw. Sorry but I work in quality assurance for a toy company so choking hazards are always on my mind

.
That being said it is not the league's place to ban them. The team however should have a particular interest in this if they think their players are endangering themselves.
It sounds silly but if enough people do something dumb like chew a plastic straw while running around, someone will get hurt.