Everyone, please, just stop
Particularly, I would like to address the people who want to contest the validity of the initial statement. I'll put it bluntly: You will continue to use this term whether or not anyone else makes a persuasive argument as to why it is not a valuable criticism because you have given it your own definition and it is easier for you to summarise things that way. And you know what? That's fine. Just please, don't use your personal use of the term to justify the cluttering-up of this forum with more "Is My Character A Mary Sue?!" threads. Those threads are pointless for exactly the reasons that you see illustrated here.
Stop beating this horse and let it die already.
This also goes for the other side of this argument. Continuing to engage in this debate only helps propagate further discord, and as much as watching Internet DRAMA™
unfold warms the cockles of my black and poisonous heart—and believe me, it's fun
—I'd rather we saw some actual variation as to what the conflict is focusing upon.