I fail to see how the males aren't just the female stick figure with short hair. Your viewpoint is at fault here, not the comics.
I see what you mean in a way - that the male stick figures don't have long hair. Again, though, this is only your viewpoint - very rarely is the stick figure's gender actually mentioned in the text of the comic or otherwise. Besides, not all females have long hair, many of the not-overtly-female stick figures may also be female despite not having long hair. Only your viewpoint, again.
The internet: where you can argue about the gender of stick figures.
Well, a couple of things here. Firstly, when the gender of a character is revealed, it's in line with what I've said. There are no long-haired males or hairless females.
Secondly, long hair denoting femaleness is a cartoon trope and that's how it's used in xkcd (note my issue is not the trope itself here, but that it is used by someone who says they're passionate about equality). Using your argument, you could argue that the cartoon characters with long eyelashes and pink bows in their hair could be male, but of course in real terms that's never how they're seen.
I see what you mean in a way - that the male stick figures don't have long hair. Again, though, this is only your viewpoint - very rarely is the stick figure's gender actually mentioned in the text of the comic or otherwise. Besides, not all females have long hair, many of the not-overtly-female stick figures may also be female despite not having long hair. Only your viewpoint, again.
The internet: where you can argue about the gender of stick figures.