I think it's quite ominous how some people talk about it. The head of interactive brokers had to stifle his laughter to himself on a phone interview when announcing futures on the platform. Warren Buffett has called it rat poison. If they're privy to gossip that leaks from what agencies and the government are planning to do then it's going to be terrifying when the trap is finally sprung.
I think the US is allowing it for now because of the huge paper-trail that it creates and how easy for them it will be to analyze all of the money flow in and out of crypto. Crypto trading also has enormous tax implications in the US and elsewhere so a lot of governments are probably looking forward to collecting the tax bills which will create a demand for their fiat when that bill has to be paid.