TV Tropes goes into some detail as to why the term has lost its meaning, but the gist of it is that it was originally intended to describe perfect female avatars of authors writing fanfiction, since at that time many online fanfictions were written by women. The term could also be used for perfect male author avatars (Gary Stu), but this term never saw wide usage since there already existed a term for this character: Action Hero (James Bond, John Matrix)
LOL! This is a ridiculous attempt at equivalence. And that’s the last I’m saying on this subject.
Thank god! Now we can all talk about Mary Sue shitwriting in peace!
The thing that’s most annoying about the “Rey phenomenon” (aka “Operation Squirrelface”) is that she’s not fulfilling any actual wishes of girls or women. She’s specifically designed to engineer and instill new wishes into a henceforth non-existent female fanbase.
And the committee responsible for her inception is so clumsy and obvious that they lacked any ideas of how to create this Herowoman for a New Millenium without making her an omnipotently overpowered Mary Sue avatar. It’s facile, lazy, dramatically bereft, and leaves nothing of emotional impact to take away from the movie.
And she’s not as cute as Leia '77.