Its amazing that so many programming contributions came from so few people
Not to burst the balloon or start a row but isn't it amazing that many are middle class, rich, white, straight men?
Not in the slightest actually.
For the Scandinavian contributors, they are a socialist largely homogeneous society, vis-à-vis the vast majority of people from that demographic are white and middle class.
In the US it's much the same for a different reason. In the US, this type of work is generally the realm of academia or post-academia, in which the prevailing demographic is both white and middle-upper class. Additionally, post-secondary schooling is provided by the state.
As to the straight comment, that is harder to quantify, one way or the other. Simply put, the information isn't generally available. As a field, although predominately male, sexual orientation has rarely been a huge focus, one way or the other. For one rather extreme example, Danielle Bunten Berry, author of MULE and Seven Cities of Gold had gender realignment surgery. There are plenty of openly gay programmers now, and some in that list may in fact be gay. Many of them are products of the 60-80s though, where coming out of the closet wasn't exactly the thing to do. Long story short, sexual orientation means so very little in the context of programming accomplishments, it simply isn't mentioned or generally relevant.