What has happened is that people have protested the perceived degradation and destruction of this country in varying ways. Some have latched on to "patriotic" symbolism in order to justify their views and/or intimidate people into compliance. Others have gone the opposite direction, having seen this abuse, and decided not to participate in the worship of flags, songs and other symbols and rituals that would denote acceptance of the current regime.
How are you so stupid you aren't aware of this basic truth?
We also learn and change, as people and as a collective. So, whereas in other times, we may have mindlessly agreed that a sporting event would be a great time to promote patriotism and market the military ... today more people are realizing that this is an unnecessary, and maybe unwanted, commingling of things meant to brainwash folks. As America is supposed to stand for liberty, freedom, individuality, etc. ... not joining together to worship something in a cult-like manner might be looked upon as a positive, rather than a negative. And even if it's not looked upon as a positive, we should also respect these American ideals enough to not assault others when they speak, think or act differently than we would like or expect, as long as they aren't acting in a criminal, or civilly actionable manner.