my tone was harsh but I maintain it was appropriate
It wasn't, by the site's guidelines and patient explanation by a moderator. These aren't laws of physics, just the norms of the venue. Would you 'maintain' it's appropriate to show up at a stranger's funeral waving a lighter and yelling 'Freebird'? Same thing.
Meanwhile, I was equated with somebody tacitly approving of segregation. Because I'm telling someone else that it's more productive to understand why this is happening than look for retribution.
Civility is about more than tone. hsod's tone was fine but his comment certainly wasnt; my tone was harsh but I maintain it was appropriate for the kind of accusations I was replying to.