The NFL is okay with actual human scum like Tom Brady's buddy Antonio Brown but civil rights agitation is no bueno.
If Kaepernick was as good a QB as Brown was a WR, trust me, they would have overlooked it. But his career was in decline by the time he started his stunts.
Also, between his Nike deal, accepting huge settlements in his lawsuits against the NFL, his demands for 20 million dollars per year to play in the XFL (100 times what their QBs are normally paid), and his extraordinarily deep "both sides bad, don't vote lol" political commentary, something tells me Kaep isn't in this to be a selfless martyr for the cause or the next MLK... Or hell, even the next Muhammad Ali. Which would be a more fitting comparison, except Ali was actually good and determined and as a result his career was by no means ruined by his political controversies.
So being a rapist is okay with you as long as they can catch ball good? Got it.
