There is a substantial demand for money laundering and purchasing things like drugs that traditional payment processors will not allow. Bitcoin works for this n

There is a substantial demand for money laundering and purchasing things like drugs that traditional payment processors will not allow. Bitcoin works for this now. Another crypto currency could replace bitcoin, and destroy the value. If the value goes down enough, miners will switch currencies and this could leave bitcoin as unusuable with a frisbee on roof attack. To destroy crypto currencies in general you would need to solve the underlying issues and reduce demand or block money laundering and payments for illegal goods.