First, Kaepernick never disregarded any terms of his contract with his employer. Those terms don't say anything about standing for the National Anthem, nor is it a requirement even today. It's not even a requirement to be on the field.
Second, this is attacking a man. I'd suggest before doing that too widely to see what he's done with his life since then, all the good he has done. He's worked hard for social justice and many organizations, he's donated over $1 million to a variety of charities while getting matches from other athletes. He's also received the following awards:
2017 GQ Magazine Citizen of the Year
2017 Sports Illustrated Muhammad Ali Legacy Award
2017 American Civil Liberties Union Eason Monroe Courageous Advocate Award
2017 Puffin/Nation Institute Prize for Creative Citizenship
2018 Amnesty International Ambassador of Conscience Award
2018 Harvard University W. E. B. Du Bois Medal
It's fine to disagree with all he's done and to dislike him, but he relinquished the opportunity to earn millions to kneel for something he believed in. How many of us would do the same?
As to skills and meriting a chance to play, if you've seen some of the horrible quarterbacks playing today and watched any of his play, and the object was to win, you'd give him a chance. Incidentally, the other player involved in the suit against the league has been allowed to play since the settlement.
If he's anti-patriotic, anti-American, then so is everyone who has ever protested from Martin Luther King to those who protested the Vietnam War to those who have protested inadequate care for military returning from war.
The question was raised as to what would others do as employers for those who disregard rules. Well, remembering he didn't disobey any rules, I'll still answer. We do have rules for workplace behavior. They do not allow any political or social activism while on the job and in the workplace. We would handle it within those rules. Now, 5 minutes before or after work they can do as they wish. However, we also do not require any of our employees to do any patriotic or social activities. We don't bring flags or causes into the work place.