A shame, really. The thing is, the 'critic' the man was addressing was actually a friend he had a history of tongue-in-cheek verbally sparring with. This fact was completely neglected of course from any reports of the matter and now another career is down the drain. The kind of comments he made really should have been exchanged a little more privately...
Fired for telling a bad joke....that's really quite sad (I am assuming the always online DRM xbox is not really happening)
However, if what he said was true, he has been fired for confirming something he shouldn't have.
You have to keep in mind that companies such as Microsoft rely VERY
heavily on their public appearance. If you have one of your executives going around saying essentially "If you don't have good internet by now, fuck you" - even sarcastically or jokingly with a friend - in a VERY public manner...well, do the termms "PR Nightmare" mean anything to you? It's the same as that asshat that worked for the 3rd party game controller company, that guy that went around saying that he knew celebrities, game studio CEOs, and even mayors while insulting the customers. Granted, his douchebaggery was in emails, but as soon as those emails went public he got kicked to the curb.
A huge part of the job is customer relations, and if you do something that seems to very blatantly insult your customers like that then you can't expect to keep your job. If a company lets a dickhead like that say stuff like that without any comment or consequences, then the public could begin to think that said dickhead is expressing the company's real feelings, leading people to believe that the company is full of dickheads like that. As the article mentioned, he's not the first person to get fired for saying something stupid on Twitter and he definitely will not be the last. I'm sure Miicrosoft might have even been understanding to the situation as he explained it to them (which is why he was asked to resign rather than getting shit-canned), but from a PR perspective that guy had to go so the company could make it clear they did not condone his condescending attitude towards people without access to good internet connections.