Yes I really hate power playing! Gosh I hate that so much. I had this one friend who would self insert all the time and he was always overpowered. He'd lash out whenever someone called him out and refused to tone his character down.
Yeah I wish other people who self insert are open to criticism. Because half the time, the character is just you but flawless. They're not attacking the personality, they're criticizing the mary sue-ing.
To me, being criticized for my self insert is like a lecturing parent so I honestly don't mind. I just usually don't tell people if I'm self inserting or not. And if they criticize my character without knowing it's a self insert, I'd just keep quiet and take the criticsim.