maybe the starkest differences between a male and a female are not color or clothes. but, that IS the way many think.OK, I'll bite, seeing as you're going down that route.
If I want to represent the differences between a male and a female (for that matter, what are they?) I can't easily put millenia of ingrained and imposed cultural norms into a small desktop icon, nor could I even summarise the last 100 years of inclusive gender thinking (and even reducing that by omitting anything controversial, because, y'know, we don't want to alienate users).
On the other hand I could simply represent the differences between a male and a female by creating an icon that shows the differences that nobody can disagree with on any basis: the genitals.
Personally, I think the icon shows "people" in a nicely minimal and inclusive way. I'm sure it's obvious to most (even people who might get offended by the blatant use of stereotypes) that it's meant to convey males and females, rather than family (parent and child), couples (two people holding hands), just men or women (as it could be if two gender-neutral people were there), or even something more confusingly abstract (two or more smiley faces). If you can think up an alternative that's neither confusing nor offensive to any minority (as in the linked case), while remaining attractive and minimal enough to work as an icon, I think the industry will rapidly adopt it out of self-preservation as much as anything else.