It's risky and I wouldn't recommend betting on it, but file sharing and drugs haven't gone away, despite the government fighting them for many years. The exact mechanism for trading bits over the Internet that other people don't want you to has evolved since the days of Napster, but music and video for free over the Internet are more accessible than ever. The other example is the War on Drugs, and we're right in the middle of an opiate epidemic, so you tell me how well that's going.

Bitcoin is backed - by the opposite of the government - the DEA keeps cannabis, cocaine, and heroin illegal, which means that Bitcoin is actually useful for moving money around for drug dealers and terrorists; anyone who can't use the mainstream banking system due to prohibition by the US government. (North Korea is another example of who's not allowed to bank.)

However, this does not let us calculate how much a Bitcoin should be worth, it only allows us to say that there is actually a use for Bitcoin, and it's not purely speculation.