It's fucked up to kick people off of teams or otherwise fire them or whatever, whether they choose to kneel or not.
I disagree that kneeling is a sign of subservience to an ideology, I consider it instead a form of peaceful and effective protest. But regardless of what I think about it, it's fucked up to not just let individuals express themselves by either kneeling or not kneeling.
Do you think sports leagues should not be allowed to ban players from wearing/making political symbols while on the field?