I hear a lot of talk about this but I'm not sure I get it.

Aren't USD used to do everything illicit and illegal under the sun including pay for assassinations, war, and environmental destruction?
Aren't USD just as easy or easier to hide from the tax man's thugs than bitcoins?  The IRS has no hidden camera in my mattress. 
Don't most  "C&TO"  use USD to do business?