Long sentences do not demonstrate anything except distain for the criminal. Rehabilitation shows that not only do you recognize that what was done to the victim was wrong, but that you are also working to ensure that it never happens to anyone again. Putting someone in prison for a long time does nothing but cost the state more money and make it harder to successfully reintegrate into society in a healthy way. Especially American prisons, which are definitively proven to increase the likelihood of further criminality through their use of torture and abuse of prisoners to ensure compliance.