The tradition of patriotism is as strong in American as the tradition of rebellion.  In fact, they have gone hand in hand.    

The football players who are disrespecting the symbols of  patriotism are strengthening Trump's support and cutting their own economic throats:   They are employed to entertain an audience that is significantly biased toward patriotism, and so behaving in a manner that appears unpatriotic is not good for their business.  Trump's base of support is also strongly biased toward patriotism, so this works well for him.   In fact, the more unpatriotic the players appear, the better for Trump.    It is, in fact, unifying for those who find unpatriotic behavior offensive, whether they voted for Trump or not. 

Russian dezinformatsiya efforts have targeted American class, wealth and race divisions for over half a century.   It those efforts begin to succeed, the fault is not with Americans' tendency to rebel nor with Americans' tendency toward patriotic display.