My two cents on the Kaepernick controversy.
Kaepernick would have been in the league after 2016 if he hadn't kneeled. He was better than plenty of backups and might have even been a low-end starter somewhere. But even if a team didn't care about the kneeling, there was no way anyone was going to sign him because no organization wants a media circus around their backup QB. It would have been a massive distraction for a player who hopefully would never have seen the field. If Russell Wilson or Tom Brady had kneeled, they'd still be on a team because they're great players and would be worth the distraction. This is a point that I think non-football fans miss. There seems to be an impression among many that Kaep was some sort of star, which he wasn't. If he was, he'd still be in the league.
At this point, I don't think Kaep comes back unless a team does it for PR reasons. How many QBs don't play for five years and then make it back? I can't imagine there have been many (if any) QBs with gaps like that in the middle of their career. Kaep will soon be 35 years old and was on a downward trajectory when he was last in the league. His 2012 and 2013 years were strong, faltered in 2014, and then bottomed out in 2015 and 2016. I don't think he'd have much value to most teams.