Earlier quoted context omitted.
I mean, no? In this specific example, the doctor is buying instruments which derive their interest from exploiting the labor and capital of those in the offering company, and after 20 years, the doctor is just living off others work because he 'earned it'. Plus, of course, in this perfect market scenario, no crashes or corrections can ever occur.
So say the doctor fronts someone money so they can invest in a business, say buying more garbage trucks for their garbage truck fleet or something. Surely the return on that is earned income? Throwing the money at your preferred wall street instrument of choice is the same thing but with half a million layers of abstraction and redirection all of which involve middle men who either take cuts or otherwise get paid for…
No. Why would it be?
Those layers of abstraction cut out the risk such that in many cases cash is the riskier instrument.