Just because you saw it on Twitter doesn't make it so.
That statement is even truer today than it was a month ago.
So, to set the record straight on what (or who) is a Mary Sue, take a look at these posts:
Men On Twitter Once Again Have No Idea What A Mary Sue Is.
It’s a Day That Ends in Y, so a Man Is Being Gross About Female Characters on the Internet.
And just so you know, the Mary Sue phenomenon isn't just about female characters, as the first article correctly explains, but can also be male author/director's wish-fulfillment, a la Luke Skywalker. A male Mary Sue is called Gary Stu.
Mary Sue's are prevalent in stories written by author's who never progressed beyond those very first stories, when all we know is ourselves and the meager experience our pre-pubescent lives have had. We want more. For writers who haven't gotten the more they wished for, Mary Sue tends to come out in the story.
It takes a mature writer to NOT create a Mary Sue or a Gary Stu. It takes a mature man to value strength and competence in women, rather than being intimidated by that.
Speaking of intimidation by confident and competent women: WTF Fox News? Oh, wait...I answered the question WTF right there. It's Faux News...never mind. But seriously? What kind of ball-less, incompetent, weak and useless man is intimidated by...SHORT HAIR? This kind. Wow. So sad it's funny. Or so funny it's sad. Mostly, it's just messed up that anyone would watch that channel or pay such a moron money to say stupid things on television.
I wish I could write this sort of nonsense in my stories. But try it, see what happens. Intelligent readers would say, "That's too far...no sane person could suspend disbelief enough to think someone would actually say/do that."
And yet here we are.