Still 10 years is longer than his victims time on the earth.
Exactly... And his victim will be screwed up for his whole life, which may be a very long time, and odds are good that the perp has done/will do it again.
How about this for a sentence:
Let's say the kid lives till he's 75. Just to appease all of the softies out there, we split it 50/50 and give the guy mandatory time served of 37 years. If the kid commits suicide then we re-charge the guy with murder. And if the VICTIM has to serve any jail time due to "acting out" later in life, we tack THAT time onto the perp's mandatory time served as well.
Now there's a jail term I can sink my teeth into!