His views about working with students are not surprising to me, despite the high quality of Harvard PhD students. The gap in brainpower between Sidney and even an exceptional graduate student might be vast. It's worth noting that Sidney had a large number of PhD students who became prominent theorists.
I often make the analogy between teaching (or training PhD students) and pushups or running. Perhaps unpleasant while you are doing it, but (hopefully) it makes you stronger. Certainly I learn a lot from teaching, if only from reviewing the material in preparation for lectures. If the students are exceptionally good, I might even learn things from questions asked in class.
But you do enjoy working with students, or do you?Interview with Dr. Sidney Coleman by Katherine Sopka at Harvard Physics Department, Cambridge, Massachusetts January 18, 1977.
Coleman: No. I hate it. You do it as part of the job. Well, that's of course false...or maybe more true than false when I say I hate it. Occasionally there's a student who is a joy to work with. But I certainly would be just as happy if I had no graduate students. There are plenty of colleagues around here whom I can work with. There are plenty of research fellows; junior faculty. This is true all through the Cambridge area. There's not only Harvard, there are people to work with at MIT, at Brandeis, and there are some good people at places like Northeastern... places loaded with physicists to collaborate with, to talk about physics ideas with, who are ready and KNOW basically how to do research. You know who's good and who's bad. It's not a question of their being embryonically possibly good or possibly rotten. So certainly if I want physicists to collaborate with I don't have to have graduate students. Occasionally there is a graduate student who is a joy to collaborate with. Both David (Politzer) and Eric (Weinberg) were of this kind, but they were essentially almost mature physicists. They were very bright by the time they came to me. In general, working with a graduate student is like teaching a course. It's tedious, unpleasant work. A pain in the neck. You do it because you're paid to do it. If I weren't paid to do it I certainly would never do it.