It's no secret that a lot of people (mostly younger) make characters that would be labeled as a Mary Sue/Garry Stu or whatever. They seem perfect, everyone loves them, they may or may not have a tragic backstory, they ship them with canon characters, or they are a self insert, and people all over the internet hate them. They go as far as to harass the owners of these characters. But let me ask you something. Why does it matter if their OWN character is a Mary Sue? If it's a fan character for an already existing series, it will not change the canon. So why does it matter? It doesn't effect you in any way. The only person it really effects is the creator and you know what? I think we should let people, especially younger people, make mary sues. You know why? Because when we go online and bash their creations, it really discourages their creativity. Let them be, they're just having a good time. Sometimes it's an escape from reality, sometimes we want to be this perfect person we create as a character, so what's the problem with that? Maybe someone who has created a mary sue is shunned at school, or has a bad home life and no friends, so they make their character have a bad past and LOTS of friends to create an escape so they can feel that even with a terrible life they can still be loved and have friends. And there could be so many more scenarios, don't be so quick to judge someone just on a fictional character. It's not hurting anyone. Let people have fun.