Traditionally, they can point guns at the guys running the servers and tell them what to do (Liberty Reserve)
Not so easy with Bitcoin
Bitcoin's ones and zeroes don't originate in a central bank.
Which makes it harder to regulate how?
If you don't create it, you can't control it. You can make laws about it, but you still don't actually control it.
Neither do the others. There are very many "central banks" out there, and the U.S. creates money out of thin air just as successfully as people mine Bitcoins out of thin air.
Unlike the creations of the central banks, there's an end to Bitcoin's creations. The value in this model is seen in Bitcoin's steadily rising and holding price.
If you believe that speculative bubbles constitute value, sure...
All monetary systems are speculative bubbles. Some just have the backing of a government to give support to the bubble. The last guy out of assignats probably felt a little foolish.
Apparently you have no idea what a speculative bubble is.
I know enough to have already exited the bubble market that's not too far from busting.