Disclaimer: I didn't read the original post, so I'm not sure where it was in your post that the word 'asshole' used to live.
In my circles, at least, 'don't be an asshole' and 'you are being an asshole' is harsh-not-mean, while 'you are an asshole' is mean-maybe-harsh. The explicit declaration of state of being, rather than observation of behavior is the differentiator.
