I can't say I know every detail of the case but I don't recall anyone getting killed or even hurt by Mr. Ulbricht so in my mind the punishment does not fit the crime. IMHO the death penalty should be off the table completely (go Nebraska!) and life in prison reserved for only violent offenders. You can argue that he enabled people to harm themselves but I think that's stretching it. If people want to take drugs, even take too much drugs their going to get it somewhere. If drugs were legal and treatment of abuse the focus instead of punishment Silk Road wouldn't have existed in the first place.
Even by the bloodiest of bleeding heart standards, contract killing isn't some victimless crime.
Because, even by the "Hang them by the neck until they are dead" gung-ho standards, you generally have to be convicted of something before being punished for it.