I think the whole thing is an extension of Kapernick's personality. In his first season, when I saw him play, his style was extremely unorthodox. He would make passes of course, but frequently would tuck the ball and run with it, often taking defensive players head on in bone crunching collisions.
For a quarterback in the NFL, he was gambling wildly with the play and his health and the gambling paid off that first season.
However, though his unpredictable play may be hard to defend in the NFL, a quarterback who plays that aggressive style of running and smashing defensive players is going to be injured badly. No doubt his coached reined in his style. And as all football fans know, it turned him into a sub-standard QB barely hanging on to his job.
Just like that first season when the team was losing or barely hanging on to a slim lead, Kapernick's instinct is to do something showy, unorthodox, reckless and fraught with risk that may pay off in a big way...
But this time he's not going head to head with a linebacker, he's going head to head with the NFL fan base and will not survive this particular collision. Just as he can exercise his right to politicize an issue to the NFL fan base, the NFL fan base has the right to marginalized him.
He doesn't give a hoot about BLM, shoot, he was the one penalized for unsportsmanlike conduct using the N word in a game. He's just another example of the Peter Priciple in the NFL where a player with vast physical gifts but with little true talent and very marginal judgement makes a brief flash but fades rapidly. And sometimes fades with ignominy.