Diversity never works and these protesting football players recognize that on some level.
They choose to disrespect a symbol of the USA because they inherently know that the USA is not for them or about them, and yet they demand that they be included. They may be a part of our shared history but they know that they are not a part of this nation and its culture because a nation and its culture consists of a racial tribe, one which is distinctly Western European and not African, Hispanic or Asian.
These football players lament that the US is actually a racial, tribal nation and they want racial and tribal unity but they will never get that from people who are not of their tribe, nor should they. It’s like an Englishman growing up in Japan and participating in its economy but lamenting the fact that Japan is for the Japanese and that he’s not included in all the native Japanese activities or represented in Japanese media. He then demands that they change who they are to accommodate the minority British presence in Japan. It makes no sense.