The author completely fails to reflect on why people commit crimes in the first place. Apparently some people just have a higher innate propensity for breaking the law that goes down with age. In practice, people commit crime because they have to, it seems like a good idea to them at the moment. Older people commit less crime because they tend to be at a much more stable position in their lives than teenagers. Perhaps the right thing to do is to make crime unnecessary by lifting communities out of poverty, encouraging the growth of tight-knit support networks and giving people more opportunities for a comfortable life. Not taking more years of life away from people.
If this is true, you'd want to imprison everyone until they hit some arbitrary age. Why not go all the way?
Goes against most of the research in Criminology & Criminal Justice. Some pretty bad takes here.