why should we let them get away with attempted murder with a measly 5 years
In my opinion, it seems like a lot of people tend to think there are no such things as human criminals. Is the solution to every crime to just lock up the perpetrator and throw away the key? How much does it cost to give someone free food, shelter, and healthcare for basically their entire life? 5 years in therapy would not only be cheaper, but at the end of those 5 years it's highly likely they'll have been cured of the desire to murder for online characters. They'd be better off by being grown up in the first place.
When you're a child, grasping the concepts of pain and fear is hard in a sheltered life, and it's naturally harder to separate imagination from reality when young. Granted it's almost never as far as to take an imaginary character's word as to take another life, but they still should not be treated as mentally competent as adults.
Criminals are people too, and don't need to be dealt with by stuffing them into a prison for most of their lives.