Burningbird � Guys Donât Link is an interesting (and hilarious) article on male bloggers obsession with links ('Mags, are you telling me that guys equate links with their dicks?'...).
Personally, though, I think a large reason why the perceived "old-boys" network of "alpha bloggers" is so male dominated has a lot to do with the traditional gender division when it comes to technology usage - the large blogs are almost all dominated by geeks or at least tech savvy people who's been involved with technology for a long time.
That alone will heavily skew things.
That said, I do think that there's a lot to be said for some of the more, ahem, creative explanations as well... Some blog because they love to write, and will write long articles with few links.
Some blogs for publicity and traffic, and they'll focus on linking because linking to other peoples content lets you produce a perceived high value with less work.
But if you DO write long articles, you still owe it to yourself to get it out there, and adding outbound links to interesting material directly connected to what you write is a great way of getting people to link to you, and also of getting people to discover you (the power of the referrer log is great...)