I agree with you that JD shouldn’t be castigated, but unless you are black then I wouldn’t engage in discussions about the status of words that have never been used against you and that don’t refer to your history of oppression.
For black people, the word obviously does hold special status, just as for disabled people other words that have been hurled at them and those like them and that have a long and horrible context hold special status.
But only one word was used by John that refers to a specific group of people on this occasion, and that was the N word and it upset people. Which is why we’re talking about that, and not about words for white people or whatever.
So lets let black people and disabled people all have their say, and try to all say what we have to say respectfully and with understanding and come to a place where if we can’t agree, we can at least agree that there are no villains here.
I realise that is a big ask for the internet, but let’s try