Its a clown statement. Players can't express themselves? Funny I remember Ray Knight crossing home plate to crowd of players jumping all over him in 1986. I remember Luis Gonzalez getting mobbed in 2001. I remember Jim Abbott pumping his stump in 1993 after a no-hitter.
The game began with men who - in almost all cases - were not paid very well and didn't have any great alternatives to a playing career. They got paid as long as they produced. And they were bounced when they could no longer do so. So it was skill, production, and pride that drove these guys, along with the ability to travel, get laid, and make some ok money. If someone showed them up on the field, that guy got punched, spiked, or beaned. We're talking about 170 years of history.
So if a guy wants to showboat after hitting a HR in the 7th inning while his team is down 7 runs, then he shouldn't complain if he gets pegged.
Cam Newton and the other guys aren't showboating unless they are up or they are in the lead. If a player makes a play that is a difference maker, I don't see any retaliation.
So if Bryce wants to stand up for some of the real idiots in baseball that celebrate when it makes no sense to do so, then so be it.