Absolutely there are reasons to complain about the system - two important areas are consistency of sentencing, and rehabilitation while incarcerated. I don't think anyone is really disputing that, though I'm sure there are people who would argue that what you are saying shows that other people get too short a sentence, not that this person got too severe a sentence.

But when there are problems with the system, they need to be addressed as just that - problems with the system, not by taking an approach of advocating that this person or that person should get a free pass (or discount so to speak).

Me? I still get the feeling you are obsessed with the innocence of kids, and it's affecting your ability to see reason here to a degree. Maybe the kid is just a sociopath to start with, and should treated as such - normally I would expect some kind of psych assessment to be done in such a case and taken into account in sentencing. That's the usual procedure. Perhaps it's one of those cases where the USA has vastly different laws from state to state, which is something that will frequently result in cases of apparent injustice.