Actually MLB nor NHL have rules that require players to stand for the National Anthem. Only the NBA/WNBA have rules that prohibit players from taking a knee.
I agree it's a no win situation for both the NFL and the players now. Like I said, Trump checkmated them. Kaep quite honestly IMO blew it. He had the focus of the sports world on him along with a few other players, and they blew it. They had what they thought would be a silent protest going even though it was still a very loud statement in of itself. So instead of owning up to such a loud statement was being made, they tried not to poke the bear. Instead the following year the bear came and poked them. Those players should have taken the window of opportunity they had, and really worked the media circut. Instead of ensuring their protest couldn't be misinterpreted, or that their message would be heard, they decided to try and continue this very loud, silent protest, and unfortunately Trump in one simple statement and a few pointed Tweets, for all intents and purposes changed everything.
Was Trump wrong for what he did? Not at all, he strengthened his base further, he will be able to claim that "he fixed" what the NFL couldn't fix and suggested players use other ways to talk about social issues instead of not supporting the our troops.. Support him or not, he's done a masterful job of making it un-American to use the National Anthem as a way of protesting, even though, that actually may be one of the most American things you and I have the freedom to do.
He wouldn't take his badge or gun off because those cock suckers don't fight fair. But if he did I'd be down. Fuck the police and their white washed fan boys.