The fundamental insight and imperative that came from the Enlightenment was that reason is the sole engine of human progress. The University is, by definition, an institution that ought to be a champion of reason, and its extension.
Research is the extension of reason par excellence.
For Ph.D. holders to eschew research is to betray the Enlightenment, and perhaps even the possibility of human progress. All of us are noble heirs of the Enlightenment's legacy. It is only a matter of degree. But a professor who takes seriously that reason is the sole engine of human progress will be committed to scholarly inquiry. To not be committed to this suggests that one should pursue another line of work.