Liberals missing the point?

I caught a part of an episode of PBS's Need to Know while waiting for the Jimmy Kimmel Lost special to come on. (A special Q&A with the actors who were present tonight should be available at Hulu.) Some researcher in neural development was talking about adolescent brain development, and how this should be studied more so that more "fair punishments" can be determined for adolescents. While it is the case that adolescents do not look at the long-term consequences of their actions, etc. as well as adults, this is due to the lack of formation. The first mistake is to think that this is a result of brain's structure (rather than being a cause of the brain's maturation as an organ). The second mistake is to look solely at the maturity of practical reasoning (and by extension, the agent's intention) as the standard for determining what is a just punishment. Adolescents may still be learning how to exercise practical reasoning, but the importance of the first precept of the moral life, which is proper to the virtue of obedience, has not been lost. Even if they are still learning how to determine means and ends and cannot do this well yet, they can still obey the law. They are properly punished for disobedience. It is the mistake of liberals who subscribe to an exaggerated notion of autonomy to think that the only law that is valid for the individual (and the basis by which their actions are judged) is determined by the individual himself. Because of this notion of autonomy, obedience as a virtue is denigrated or even criticized for being a handicap to moral development.