[Merrill]

PhD students tend to adopt the value system of their advisors mentors and others at their university.

Advisors value academic careers, partly because that is usually the only thing that they know, and look down on PhDs that go into industry or change fields as failures.

Advisors are also judged on the academic success of their graduates, who ideally go on to famous careers at notable universities. There is a branch of academic politics that governs how advisors place their best students where they will reflect well on them.

The net result is that graduate students have few mentors advising them on the possibilities outside of academe. The "failures" are left to make it on their own.