I can't help but think it has to do with how smart a person is. Smarter people are more likely to succeed in skill based tasks like some video games. And smarter people are less likely afraid of smart women because they don't care about hierarchy and care more about meeting interesting people of whatever gender. But I might be projecting myself there.
If you want to read this as offensively as possible you could say that successful men are just as afraid of women outperforming them, it just happens a lot less often. And they are only nice to women below them which happens more often when you're at the top. So, basically men are pigs when threatened in their hierarchy and nice when women are below them "as they should be". I sure hope this is not the reason behind this behavior. It does, however, also explain the phenomenon.
