It doesn't murder the point at all and nonsense to suggest that it is. I just won't play a stupid game of 'ah but, look, here is one non-racist and you said 100% of the people are racist'.
It is not counter-productive. If people are extra racist or now racist because some footballers took the knee then, I'm sorry to say this, they may already have been racists. In fact, seems pretty productive if racists are only just outing themselves because of this.
Or is this one of those things where sensible centrists are being torn as to who to side with?
Because, of course, those are the only two negative reactions to the gesture...