Right, a mass surveillance system that's primarily used to oppress sex workers, drug users and dissidents.
Take a look at what's banned by the company where a couple very vocal authoritarians who signed that letter work:
Banks, financial services and governments having access to your entire financial history is mass surveillance. Selling and sharing access to it to other companies makes that even more true.
I'm not American and I'm not sure what that would have to do with any of this if I was.
Cash still exists despite gradual moves to get rid of it to make sure all financial activity is under surveillance.
What problem do Monero or Zcash introduce which wasn't already there with cash? If anything it's easier to criminals to screw up and there's far more info to leak.
The world worked fine before there were detailed histories available to corporations of governments of people's conversations, financial transactions and many other details of their lives. Private cryptocurrencies aren't bringing a new form of privacy. They're just the new cash.