Yes, idiots. Kaepernick was always legally allowed to kneel. Some people just found it irritating, and pro football is a private business.
Joe Kennedy, the coach at the center of the recent Supreme Court case, was fired from a public school for praying by himself, which is actually what the Constitutional right to religious liberty is designed to protect. Seriously. The point was never that no one ever hear about anyone's religion, but that the state (or state-run entities like public schools) cannot prohibit anyone from practicing their religion or require them to participate in someone else's religion.
This all came about as a reaction to the Church of England being tied to the state.
Nothing about this is relevant to Kaepernick. Stop it.