I'm really divided by this. He didn't do himself any favours and in the end he had to choose to either pursue his principles in the limelight of NFL telecasts, or, have a career. What he does outside of work is one issue, but choosing to kneel for the anthem while at work doesn't have to be, nor obviously is it acceptable by his employer.
As I said if he would have come out and apologized, decided he wanted a career and signed a contract which would allow for his immediate dismissal if he disrespected the flag again, I believe he like anyone, deserved a second chance. Appears he chose to not do so.
The best person should always get the job, but he has been a distraction and has in fact cost his owners money, it isn't a charity or some activist league, thus, he is unemployed.