I find myself agreeing with the sentiment but perhaps not the application.
US sentences are, in general, far too harsh and they rarely have any sort of rehabilitative value -- they're just revenge.
I fully understand the compulsion for retribution -- as mentioned in another posting, a close colleague of mine was murdered while attempting to thwart a burglary of his vehicle. I was very angry for a very long time about that. To an extent, I still am.
But, still, revenge produces just bitterness and more revenge -- you can only look at recent events in the Middle East to see that writ large. Writ small and personal, prolonged and often cruel incarceration rarely produces better people.
Some countries take what might be considered a more enlightened approach to crime and punishment.
Norway, for instance, has "maximum custodial sentence is 21 years (30 for crimes against humanity and only life imprisonment for military crimes)1 (emphasis mine)." How well does that work? Well, "Norway has one of the lowest recidivism rates in the world2" so maybe they're doing something right.
Having said all of that, I do wonder if the miscreant was named, say, Raul "Pirata Temido Roberto" Uvalde instead of Ross "Dread Pirate Roberts" Ulbricht whether we'd be having this conversation at all.
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1 Incarceration in Norway
2 Loc. cit.