I see some blogs show strong opposition to the idea. Arguments include that it's a violation of Freedom of Speech, that players are hyped-up, it's part of intimidating your opponents. To which I would say:
- NFL players are paid employees at work, not some buddies informally playing football on private property. Courts have ruled that employers can control employee behavior to a great extent while on the job, and sometimes even off, and some Constitutional provisions do not apply.
- An NFL football field is a place of public viewing. With modern sound equipment player's voices CAN be heard and broadcast (though eavesdropping by teams is prohibited). Or players' natural voices can carry to just the spectators on the sidelines, still capable of being overheard by others than the players themselves.
- I do hope other forms of hate speech will also be penalized. It would be hard to reduce this kind behavior if our sports heroes are using it. For the same reason they get paid millions on the power of their product endorsements, their endorsement of hate speech also carries great influence with the public.
When I was a kid sports heroes used to be called roll models for our youth. Hardly true today, more like roll models for street gangs, but the concept still lingers. And maybe what the NFL would like to restore. Gawd knows their players are some of the worst examples in all of US sports.