Your comment about point-scoring rings very true to me because, in my on-line experience, I have to say that some of the most hostile behaviour I have witnessed has come from self-called allies who seem to almost be trying to differentiate themselves and score extra points by jumping on someone (who screwed up in some manner) in the rudest/most sarcastic way they can.

And that's a long way from someone from the actual minority group in question losing their patience at being met with closed ears and "I'm offended that you're offended", which is how I originally understood the tone argument to work