He certainly appeared this way to British academics he spent time with. John Maynard Kaynes called him a maniac. Bertrand Russell called him an infection. One wonders, though, how much of that was no more than the kind of failed cultural translation so common in cross-cultural encounters.
In a new book collecting some of Wittgenstein's letters and other things, for example, we find this note to Cambridge philosopher GE Moore:
"I should like to know whether what Mrs Moore wrote to me was an honest to God invitation for me to come and see you on Tuesday, or whether it was a kind of hint that I’d better not try to see you. If it was the latter, please don’t hesitate to say so. I will not be hurt in the slightest, for I know that queer things happen in this world. It’s one of the few things I’ve really learnt in my life. So please, if that’s how it is, just write on a [post card] something like 'Don’t come'. I enclose a card in case you haven’t got one. I'll understand everything. Good luck and good wishes!"That letter could have been written by pretty much every German I know. I have made similar requests to Germans: please explain and spell out the social rules involved in X, because, God knows, "queer things happen in this world," and all I've learned is I don't understand them.
Little things, such as how long one is supposed to stay at dinner, are terrible difficult to navigate. The social cues for what's polite are near impossible to pick up. Americans here regularly offend Germans by leaving too soon; Germans insist on social engagements that are more like marathons.
In the end you just have to hope people won't describe you for the rest of history as strange and rude, and you beg people to please tell you if what they said was coded in "a kind of hint" or was honest to God what you think they said.
I'm sure Wittgenstein was intense. You don't do that much of that kind of philosophy without some intensity. But maybe some of it, the way he's been characterized now for forever, has something to do with just not knowing what the unwritten rules of acceptable social behavior were in Cambridge.
For that, it's only fair to give him a bit of a break. He was trying. And that story about the poker's probably apocryphal anyway.