It appears that there is a sense in which he is correct: E.g., early in my career I stumbled onto some of what he is saying but then didn't appreciate the situ

It appears that there is a sense in which he is correct: E.g., early in my career I stumbled onto some of what he is saying but then didn't appreciate the situation. Basically, just stay with what is hot. Get into a hot job, learn what is hot, jump to another job that wants the hot stuff, keep going for the hot stuff. This way get to focus: (1) Actually can get okay with the point of the focus at the hot stuff because that point is not very large or hard if only because what is "hot" is from a public that doesn't know very much and (2) do not have to learn computer science broadly. If take the money from learning the hot stuff, get a good Ph.D. in what is arguably the better stuff, go back to the job market, and no longer be with the then current hot stuff, then can find that your career is in trouble. Then using your actual competence in some actually important stuff, do a startup where need to please the users but not some naive public fooled by mostly simplistic hot stuff.