That's an admirable sentiment, but I personally find the section confusing. Perhaps the loose paragraphs that talk about non-white, non-straight and female could be condensed down to something that didn't seem quite as condescending and actuallly was a little more clear -- and put after a paragraph or two that talk about what you are expected to know to benefit from the text?

I don't really mind "being left out" as a straight white male that's been into hard sciences and computers since I was six (before then it was all dolls, if I am to judge by our family albums) -- but it does strike me as a little strange to read an entire page about "who's this for" and still not getting any real information other than that if I were slightly gay, I'd be more in the target audience? What does that even mean?

As a side note, I've never heard the tech/science community nor higher education was discriminating on sexual preference -- race and gender (as largely a function of wealth and old bias) -- yes -- but there's a gay issue as well? If true that's sad, and I'm glad to be made aware of it -- but I still think the entire about-page could do with a rewrite.