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.