He didn't get cut by SF period. He opted out of the last year of his contract.GetThoseKeysMilo said:
A) He can no longer rely on his legs post injury, and isn't a great passer. He didn't get cut by SF due to his political protests, he got cut because he wasn't a good player.
B) He would immediately become a huge distraction on whatever team he lands on. It would be worse than Tebow. Even if a team thinks he could be a viable backup, no one wants to deal with that kind of media attention for a backup QB.