I believe the technical term for this is ad hominem. Is it even possible for an argument to be true if it subjects the author to a witty reply? Apparently the Internet would have us believe that all such arguments are a priori certain to be false.
Er, no, it's pointing out a selection bias which means that anyone inclined to take the existence of this person writing about "why there are no girls in SF" (plus, I guess, the apparent shortage of people writing about what a great place SF is for heterosexual men to find partners) as evidence that SF is (functionally) very short of women -- which, let's face it, lots of people would -- should think twice before doing so.
Not an ad hominen at all. ajg is not trying to deny the main proposition, i.e., that there's a shortage of women.
The point is that the shortage doesn't affect all guys equally. The guys with better chances aren't likely theorizing and writing blogs about the shortage.