I'm a 70 year old white man who couldn't care less about any of the anthem protests to date. I'm old enough to have seen much more intense social actions, and I have sympathy for their cause. I've also never been a fan of anthems at sporting events.
I would argue, however, that employees don't have any right to use their workplace, filled primarily with unwilling hostage fans in this case, for personal political purposes. They have numerous other avenues - sit out games and forego their pay, assemble as a group after the game and meet the press, pretty much say and do anything they wish outside the work environment.