"Ignorance of the law is not an excuse" is a well-established legal principle with precedent going back to Ancient Rome. It does get a bit tricky when regulatory statutes get involved, but c'mon: all these businesses save maybe Coinbase are run by criminals. We're not talking about well-meaning people acting in good faith here.

Also, that all only applies to criminal statues, not civil/regulatory ones. If you're a construction firm who doesn't know that houses have to be built to fire code, maybe you'll escape criminal prosecution, but the government is going to take an axe to your business anyway.