This is purely speculation on my part as I still don't see or understand the offense of kneeling.
If our world within the U.S. Of A were one in which all were subjected in the extreme to a political dictatorship. To the point that even those called to serve in the armed forces weren't given a say or rights just like everyone else. But, were instead forced to bear the dictatorship's media, audio, and societal dehumanizations of everyone who was not part of the political party. Would you as members of the armed forces still find the strength of Will to stand for that flag? Or, in exercising the rights of an age past. Would you unit with cilvilians in fighting against such suppression, but in a way that showed your love for this country by peacefully kneeling in protest? No riots, violence marches, mutinies or bombing boycotts. Would you kneel to protest for a better, if not equal treatment as those who are part of the political party?