I can think of a couple other reasons: 1. With cryptocurrencies now blackhats have a buyer that isn't a corrupt foreign government. A lot of organizations are

I can think of a couple other reasons: 1. With cryptocurrencies now blackhats have a buyer that isn't a corrupt foreign government. A lot of organizations are quietly paying ransoms right now. It's better than the alternative. 2. Who is this Satoshi, really? Colour me a little bit skeptical that someone was able to pull off this level of anonymity for this long. I'm not saying it is likely (<5% chance), but it is at least possible that Bitcoin is the American answer to the declining power of the greenback against the Euro and Yuan over the next couple decades. 3. Map out the crime networks and scoop them all up all at once then ban or regulate cryptocurrencies. Essentially what you said. But I agree, it doesn't make sense for governments to cede this amount of power, and the small positive value that they enable (like actually being able to reliably send money to friends overseas) is dwarfed by the corruption they enable.