I am not aware that Silk Road ever had a genuine "assassination" market. Fake perhaps, not genuine.
As for "illicit drugs": Probably billions of dollars of 'illicit drugs' are bought and sold, daily, without any connection to the Internet. If anything, Silk Road made the world a safer place: There was much less likelihood of being arrested for drug deals, due to little or no human contact. And because of the concept of "reputation", chances are good that the drugs sold on Silk Road (or other subsequent 'Dark Markets') were more reliable, higher and more-consistent purity, fewer unhealthy 'cuts', etc.
So, it was a BENEFICIAL website. It simply thwarted the desire of some people who wanted to suppress drug sales and use.
Jim Bell