One, I still think telling someone that something they have done sucks is harder to do in person than online. But two, the point is that the incident in question was pretty much "you suck because your code sucks."
Telling someone their hard work and best efforts suck DOES hurt their feelings. If you don't recognize that and go around telling people their work sucks, then you might be an asshole.
>>>Telling someone their hard work and best efforts suck DOES hurt their feelings.
And so what? You think books don't get bad reviews? Movies? TV shows? School tests? It's part of life. Take the hit, move on. Do better if you must.
EDIT to add: When it comes to one-on-one being told your work sucks, the best response I think is this: "OK, if it sucks, tell me how, because I'm not yet able to see it and I'd rather not suck." That's better than just stewing in hurt feelings and never improving or knowing how to improve.
Telling someone their code sucks does not equal telling them they suck.
You are not your code.