The litmus test is not the complexity or impact of the product a professional is working on, but rather: how savvy are the customers and do they need the protec

The litmus test is not the complexity or impact of the product a professional is working on, but rather: how savvy are the customers and do they need the protection of regulation? All of the professions you named are people who hang a shingle and sell services to low-information customers. Missile systems, voting machines, and power plants are all "sold" to high-information customers that need less gov't protection. Other engineers do need certification and do face legal culpability if they are negligent in their work, but it's inherently different I think. We can talk more about that if you're interested, would like to hear your take.