Think back to your own CS professors, were any of them particular good software engineers?
I've found that Physics PhDs tend to have the highest probability of being good coders since a certain subset of them get bit by the software bug when they need to write non-trivial amounts of code to solve research problems.
I got my physics PhD in the early 90s. Physics has had a tradition of interest in programming that goes back decades. We've always had "big data," meaning big relative to the tools available at any given moment. We ran out of problems that could be solved by pencil and paper in the 1930s.
Every physics student at my college had to take FORTRAN, plus programming was assumed in many of the other courses, and we also took an electronics course that included digital techniques. And maybe the main thing was simply that programming was interesting and fun.
We've also had a tradition of learning to do everything ourselves, for better or worse. I had no access to a professional programmer.
I've found that Physics PhDs tend to have the highest probability of being good coders since a certain subset of them get bit by the software bug when they need to write non-trivial amounts of code to solve research problems.