Kamikaze Midget said:
And I think the stereotypes/archetypes are particularly challenging to be rid of in D&D, where the myths and tales the game is based on so often have a deeply entrenched male-centric (if not downright mysogynistic) angle. I mean, Save The Princess is a cliche, but it automatically assumes princesses can't save themselves.
Why is it that when a young man goes out with mystical aid and wins the hand of a princess (Sleeping Beauty) it's a sign of the Evils of Patriarchy, but when a young woman goes out with mystical aid and wins the hand of a prince (Cinderella), it's... ALSO a sign of the Evils of Patriarchy?
Mythology and especially folk tales contain female protagonists as often as male. If you're boiling it down to "misogynistic Greeks and gynophobic medieval codices," you're already ruling out a large portion of the available myths and stories. Cuchullainn, the big Irish epic hero, learned all his moves from a female blademaster. Morgan the Fey oumagicked and outsmarted Arthur at pretty much every turn. And so on. Yes, all of these characters existed within sexist conceptions of the world, but their male counterparts were stuck with societal expectations we'd consider just as ridiculous.
D&D "medieval fantasy" isn't about historical accuracy, you're correct there. But it's not necessarily about mindlessly recycling outdated themes and tale-types, either. A lot of D&D "types" are really just modern-world "types" repurposed. The frail wizard is the stereotypical bookworm from high school, with a healthy dose of revenge. Obviously the women of D&D can't be "realistic" medieval women warriors, because by and large those didn't exist. So instead they seem to be sort of "modern woman" in chainmail: trying to balance sex appeal with practicality.
Thus, the 4e women sneak a plunging neckline or a bare midriff into their plate mail at times. It may not be completely practical, but neither are the oh-so-phallic spikes sprouting out of their male peers' armor, and they see no reason why they should pay what could literally be a king's ransom, tens of thousands of gold pieces, to have magical armor specially crafted for them only to have it make them look like undergrown boys with overlong hair.
Basically, even if one accepts your argument that chainmail bikinis are wrong for the reasons you cite, it can be argued that the art style in 4e isn't just a compromise between chainmail bikinis and historic armor, but rather something more positive. And I think my interpretation is in line with the way not only a bunch of the WOTC people see it, but also the way a lot of female gamers see it: being a little sexy doesn't make you a pinup.