This is true of a lot of tech start ups - doing something that is technically not allowed, but the key difference is that to do it successfully you need to get

This is true of a lot of tech start ups - doing something that is technically not allowed, but the key difference is that to do it successfully you need to get to a scale where you can pivot to something is allowed. For Uber that was slowly changing to adhere to all the regulations around employment law and taxi companies in each jurisdiction. It's questionable that after that pivot they're a great business. In Tornado Cash I guess the equivalent would "You can hide the flow of your crypto from the public but we're still going to comply with the government AML & KYC."