The reason they don't want decentralized crypto markets to pop up is because it is the equivalent of a trade market that is unregulated. It is the same thing as a fruit market that pops up on the side of the street except it is dealing in crypto. The way to think about it is in the way of trading metals or literally anything else that can be traded and/or used as a utility of trade. They can't control it unless they cut electricity off. They (the Treasury Department) want control. I agree that a nation needs to have control over ITS OWN currency. The problem is when you start to say you can't trade other things including crypto it impedes on your liberty to trade. I think many people don't want crypto and think it is dangerous because they don't understand it. It really should be thought of not as the currency of a nation or the world but more like a stock or (Forex) currency that is traded in an unregulated fashion.... But I am a libertarian and want freedom to trade anything I want... so i digress.