I have no idea how the Mary Sue archetype can be remotely be described as sexist (it hasn’t been used to hold down generations of women if anything isolating the trope enhances female characters in Fiction) but even if it is it has nothing to do with the thread title so perhaps we should stop going on about it or open up a thread in off topic.
Perhaps you shouldn’t have made your point and then suggest we not discuss it here in the same post?
Also, read the article I linked to if you need help understanding. Or any of the numerous other similar articles.
JEDIT:
http://originaltrilogy.com/topic/EP7-Spoilers-Why-I-dont-think-Rey-is-a-Merry-Sue/id/47543