&gt;Most likely because if you are doing ML and do not have a PhD (or previous experience), you are just looking at calling a library function that you do not understand.<p>I&#x27;m assuming that&#x27;s your interpretation of the industry mindset, and not a view you personally hold.<p>IMO it&#x27;s a naive assumption, and it would be trivial to test for it in an interview.<p>I have an interest in ML for a specific domain, no PhD, and it wouldn&#x27;t cross my mind to try to use it as a set of shrink-wrapped library functions.