I don't believe that for a second. More likely, infosec tends to attract more results-oriented personalities. To generalize, "who cares what you look like as long as you're good?" As a consequence of that, infosec tends to be a lot more welcoming than other groups I've been around. As long as you act nicely, people generally don't care if you're man, women, both, neither, or a gay horse. And it seems like there's been a feedback loop over many years: that acceptance drew more out-of-the-norm folks, which made it more accepting. Lather, rinse, repeat.

But in any case, I thoroughly believe the "joke": turn people away because they don't look / act / think like most others, and soon the very best infosec talent will want nothing to do with you. And based on this article, I'm guessing that's true for other extremely technical fields, too.