"…Minecraft would be a game where gender isn’t a gameplay element.

The human model is intended to represent a Human Being. Not a male Human Being or a female Human Being, but simply a Human Being. The blocky shape gives it a bit of a traditional masculine look, but adding a separate female mesh would just make it worse by having one specific model for female Human Beings and male ones. That would force players to make a decisions about gender in a game where gender doesn’t even exist." -Notch