I haven't RTFT but on the first page a couple of posters were moaning about how nowadays people are censored for saying racist, disablist things.
Um, no. People are nowadays more often challenged for spouting racist, disablist, sexist bollocks. This isn't a bad thing.
If you're being challenged by a member of a minority or other group for saying something ignorant - don't instantly get defensive and deny any intent at offence, and try to cast those challenging you as horrible attackers, or oversensitive.
Understandably you're going to be upset, they're not pointing it out for the fun of it. Your intent may have been innocent, but, and I mean this kindly, your intention isn't the point. Your words have weight, and bear in mind members of groups hear this sort of stuff a million times over - so first just listen to what people are telling you about what you said. Criticism isn't fun to listen to, but swallow your ego, examine what came out of your mouth, and if on reflection you messed up, apologise.
You can't know everything, but you can learn. Denying you did anything wrong is bad form, as this is a complete dismissal of their POV, and by extension, a dismissal of their life experiences. It's a form of gas lighting and not an okay thing to do.