Disclosure: I went to DEF CON 2 in 1994 when I was a shy 15 year old and there were no women around and apparently, better manners.
A bunch of the people present think that they can hack systems. And have read articles about pickup artists and have come to the theory that what women really want is a guy who has the balls to be up front about what he wants. So being over the top seems to them to be a way to hack human relationships.
Maybe there are some women who respond well to that. I don't know. I've never had a reason to try to act like that. But even if a hypothetical minority of women will respond well, the vast majority simply won't. And you'll leave a trail of offended people behind you.
So overconfidence combined with stupidly wrong theories about what women will respond to, and a complete lack of respect for feelings hurt lead to over the top jerks. There are not a lot of these. They are probably a very small minority. But even a small portion have a disproportionate impact on the experience that women will have.
I read "The Game" by Neil Strauss as part of my paper and the guy he follows in it, Mystery, is very emotionally under developed. He throws temper tantrums continually. Both Neil and Mystery seem to have huge self esteem problems and use pick up artist tricks to try to make themselves feel better without ever addressing their core problems.
The women they meet on their journey, according to them, are fantastic looking, but they too have huge emotional problems, mainly very very low self worth.
So you have these guys who are pretty intelligent from a sort of book stand point and these girls who have very low self esteem. In the end everyone in the book seemed to be worse off. Many of them spiral out of control and end up pretty bad.
It was pretty sad. :(
Also, those of us in the brainy set generally equate our rational inner narrative as the total of our self, underestimating how much of our behavior is driven by habit and unconscious reaction. This makes us very good at explaining away our poor behavior when it's exposed to us.