Every new technology , like the internet , can be used in a good way or in a bad way. On the internet there are scams , drugs , and many other illegal things. Does that mean we have to shut down the internet ? Of course Not.
In addition the real currency used by criminals is FIAT in cash (usd , euro , gbp ...) because it's not traceable. On the other hand , cryptocurrency transactions are made public on the blockchain.
Maybe some dictatorships will try to ban bitcoin although it's very hard to enforce because exchanges can just move to a place where it's legal , or be decentralized. But smart governements will just regulate it and embrace it.
