Well, mark up another victim to DrKupo. He's a troll of the highest order. A dick, yes, but also a troll in every way.
You have to put yourself in his shoes, and realize that this ENTIRE thread is pleasing him to no end (including this very post). If it were sent to him via PM, he would have been a bit riled up, but still enjoyed the fact that he upset someone so much. But posting it in public view makes it exponentially better to him.
Everyone who has encountered him knows him to be a giant horse's ass. But if you understand how trolls think, you'd know why this is. Think of it this way, the more he can get under your skin, the more he'll keep digging. I've personally talked with him a number of times, and he generally doesn't pick on me (but given the chance, he'd probably try with this post).
Why? Because it doesn't effect me. I know he doesn't even mean half the stuff he says. I know that he's only doing it for attention. When people get angry over it, and fight back, it's like catching a fish. If you simply kick/ban trolls, and move on, you've effectively cut off their food. But by falling for it yourself, and responding with personal attacks-a-plenty, you've become a new target, and made the whole situation worse.
DrKupo isn't going to "get better". He isn't going to leave by telling him he isn't welcome. You might as well try to put out a fire with a bucket of gasoline. Do what you gotta do, and move on. That's it.
In short: this is simply fuel for the fire. Nothing will change.
(for the people I've talked with about a certain "other" member here, yes, I fell for that troll pretty badly. So I'm not innocent of this either. It happens to the best of us.)