Also he's 19 now, and most of this apparently happened when he was 14?
I don't think anyone is (or should be) saying this has to be define the rest of the his natural life, but it was literally just 5 years ago. It didn't just become nothing the moment he turned 18.
5 years makes a huge difference between 14 and 19. People can change dramatically over this period of time. It's very reasonable to want to see evidence that someone has changed their ways and that they want to make amends for harm caused when they were younger, but you have to allow people to grow.
Again I don't think the standard being applied here is that he can't grow or is forever barred from political office for something he did when he was 14.
But, especially in running for political office, it's not unreasonable to think not enough time has gone by for this to be ignored.