Actually, this is ok. The original kneelers were attention seekers. Once everyone is kneeling, it loses all meaning. In fact, eventually kneeling will be the way to show respect to the flag, and the protesting athletes will the stand to show solidarity. Kind of similar to how #blacklivesmatter is now standard ad-speak, no different than “your mileage may vary”.
No, the point of the kneeling is that the announcer usually says: "Ladies and gentlemen, please rise for our national anthem". Staying seated or kneeling is an "in your face" refusal to stand and show respect. It is the equivalent of the middle finger to the flag, the country and all those who are standing.