His argument essentially boils down to: "Don't make Bitcoins illegal, but discourage use and shame those who accept them as payment". So let's imagine a world

His argument essentially boils down to: "Don't make Bitcoins illegal, but discourage use and shame those who accept them as payment". So let's imagine a world where this happens. Most vendors shut down operations, people dump their coins and the price of Bitcoin crashes and stabilizes at some sub-dollar amount. Now, only criminals make use of Bitcoin. Well, nothing has changed. Consumers of drugs purchase Bitcoins for use on Silkroad-esque sites. Sellers accept Bitcoin payment for drugs and then sell the coins back to other individuals wishing to purchase drugs. The use of Bitcoin to facilitate illegal activities does not require mass adoption. As long as there are enough people participating in illegal activities to keep exchanges liquid, nothing will change. In short, his solution accomplishes nothing. It doesn't reduce Bitcoin's ability to facilitate illegal activities at all.