In spite of the fact that America has not been good or fair to black people, African Americans have always remained loyal to this nation. African Americans have fought to show their love for America and to hopefully "earn" their way to full citizenship. Nothing, though, not even fighting against Nazism and Communism, or fighting for the freedom of other people in other lands, has ever been enough to erase the presence and the scourge of white supremacy and its child, racism. Black soldiers have served as valiantly as have white soldiers, only to come home and face more segregation and outright discrimination in jobs, housing and education.(http://www.pbs.org/wnet/african-americans-many-rivers-to-cross/history/what-was-black-americas-double-war/)
We have been "good enough" to fight for America, but not good enough to be allowed to be full participants in American society. Fighting notwithstanding, we have been denied full access to perks of free Americans, including being able to get loans for buying homes and starting businesses, having access to quality education and getting good jobs. This reality is what fueled the actions of the late Muhammed Ali years ago, when he refused to fight in the Viet Nam War, and it is what is fueling Colin Kaepernick and, slowly, other African American athletes in their refusal to stand during the signing of the National Anthem.
Too many white Americans seem unwilling to just admit that racism has left deep scars in everyone - black and white - and has traumatized the African-American populace for generations. The damage has been great and deep but in spite of that, African-Americans have continued to fight for full citizenship and dignity.
There are so many stories of African-American men coming home from fighting in America's wars, only to be relegated, again, to second-class citizenship here. There are so many stories of African- American soldiers who were brutalized by white people upon returning home from war - even though they were still in uniform - with white governments doing nothing to the perpetrators.
There is too much unwillingness on the part of too many white people to ignore America's history when it comes to race. How could anyone not feel some sort of angst upon learning the full history of the National Anthem, and the verse where it celebrated its put down of the efforts of slaves to earn their freedom? (http://edition.cnn.com/2016/08/29/sport/colin-kaepernick-flag-protest-has-history-trnd/)
Are African-Americans really expected to celebrate their oppression by white supremacists?
The history we are all taught has left out so much of what really happened to not only black people, but to brown people, indigenous Americans and women. We have been carefully manipulated to believe that "freedom" is and has always been a mainstay of all Americans, but a deeper read of history shows that not to have been the case.
During the Civil Rights movement, a group of young African American girls, ages 13-15, were rounded up and put into prison for protesting in Americus, Georgia. (http://gpbnews.org/post/girls-leesburg-stockade) The story of them being herded into a prison cell, being held there for two months, deprived of proper sanitation facilities and products, made to sleep on the concrete floor ...is not told. Theirs is not the only story ...and yet, people like these survived horrendous conditions and came through those experiences and supported America, even as they pushed past America's ugliness.
So, it's disingenuous for white people to say that someone not standing is being unpatriotic. African-Americans have been some of the staunchest patriots of this nation. We have stood up for America, and stood for American ideals even as America rejected us and made our lives a living hell. Too many white people believed - and may still believe - that God made America to be a white man's country, and justified their treatment of African Americans on that basis. That belief fueled many of their racist acts, but regardless, African Americans have kept on pushing for justice.
That we have not yet gotten justice is why some - but not all - of us cannot "honor" the National Anthem or the Pledge of Allegiance with full abandon. We know that in spite of the song and the pledge, we have been second-class citizens, with full government support of the same. When that changes, when governments work to make the ideals of Americanism honored for all Americans, perhaps then those who are strong enough to stand against hypocrisy will be able to believe in the country the way the privileged have always been able to do.