Once again, you don't give up your constitutional rights because you take a job. Your employer cannot force you to salute a flag any more than it can force you to pray. That is unless saluting a flag and praying are in your job description or contract. Anyone would have a very good court case challenging this notion.
I'm not the one who is confused. "The man doing his job in the 2nd picture" is not beating or shooting anyone. He is protecting a group of people who would likely roast him on a spit if they could get away with it. It is quite sad that you don't see that.......or won't.
You don't give up your constitutional rights because you take a job. Those players should take the NFL to court and we'll all see what side the law falls on.