Because people are fallen and sinful (Genesis 3, Jeremiah 17:9, Romans 3:23, 1st John 1:10), the veneer of civilization is thin even in first-world nations. When a sizable portion of a population adopts an erroneous viewpoint (like believing everyone and everything is racist) widespread suspicion results, which can cause the thin veneer of civilization to crack. When the veneer of civilization cracks all the sinful gunk and goo that simmers just below the surface of humanity leaks out. When that happens, all hell can and sometimes does break loose.
The football players protesting today are not marginalized poor people living out their lives on the fringes of society. They are in fact some of the wealthiest and most advantaged of all Americans (black or white). If they wanted to do something meaningful to solve the plethora of problems troubling the black community they certainly have the power, influence and financial resources to do almost anything they wanted to do.
Nor is the over-the-top activism about our racist past. I am no fan of Confederate statues or symbols (I once told my son’s friend never to wear a confederate flag t-shirt in my house again). That said, those statues have been sitting in parks and public spaces for decades (including eight years under a Democratic president) and only egg headed professors and a few of the deeper thinkers in the social justice warrior movement cared all that much about the symbolism or even the existence of those statues.