I don't think this meets specification. "it never has been and never will be economically viable" scans as handwavy, and I've yet to see anyone calling for "ditch diggers" (job automated out of existence by heavy equipment several decades ago, btw) a wage equivalent to what an MD makes. Your assertion, in essence, appears to be that people get paid low wages because low wage jobs exist. That does nothing to explain why a job sufficiently important to require a human being to perform is low-paying and so far nobody has advanced an explanation that takes into account historic levels of corporate profits and income inequality while wages have been basically stagnant since the 70s.