Macadia
The criminal probably did not get in the car with the intent to kill someone but acted his age, or younger, and was too immature to handle the responsibility of driving a vehicle. Do parents have to agree to let their teenager operate a vehicle?
The stiffer sentences would be reserved for those evil ones who have a plan and intent to murder, mame or harm others and are repeat offenders that can't be rehabilitated. They are locked up to protect other citizens.
To some degree I agree with you, this idiot did not go out with the intention of killing someone. What he did was thoughtless, stupid and immature and he deserves punishment, but what would a long prison sentence serve? He would be mixing with hardened criminals and would probably come out with a much worse attitude. The Driving ban should be harsher and with a need to pass another test in the future together with an advanced driving test and he should be prohibited from driving cars without a speed limiter on them for a number of years after passing.