Thoughts about Mary Sue

I've read a bunch of very interesting posts recently about how Mary Sues are not actually that big of a deal (beyond being generally bad writing) and maybe telling girls not to write overly awesome female characters has some underlying misogyny. This post is not about that but is partly inspired by those posts on that subject:
Oh Mary Mary and the slash writer ponders female characters.

EDIT: Valid question: what do I mean by Mary Sue?
I personally would only call a character a Mary Sue if it fit all the major hallmarks: an original female character in a fanwork who is implausibly unique, talented, and popular, badly written, and has the canon characters and plot warp around her to fit the author's wish fulfillment.
But I have seen the accusation leveled at any original female character who is in any way cool.

So, two thoughts:
( Why gender? )

( Mary Sues in Dragon Age: Origins fanfic )