//one's a voluntary signal that a few choose to use, the other seems to be a compulsry act//
It's not a compulsory act though. Many players, and indeed teems, have stopped doing it. Middlesbrough made a press statement to say they will not be taking the knee anymore, and stood while their opponents did it last night. When QPR director of football Les Ferdinand, one of the most famous black players of his day, urged the act to stop as it's meaning had become diluted, his players asked to be allowed to continue.
It seems to be a purely voluntary act, and considering the OP recently began a thread about freedom of speech, I'd suggest freedom of expression also be a basic right for all.