Kaepernick has every right to act like an a-hole and sulk while the anthem is being played. Fans have the right to disrespect him for it.
As for him trying to make a statement about how "oppressed" his fellow black citizens are in this country... his birth mother is white, as are the adoptive parents who raised him. Oh; and he's a multi-millionaire. Must be an ordeal for him to be so oppressed because of his light-tan skin color!