Completely off topic, but I really don't understand the demographic of physics educators that are resistant to Dirac notation in a first QM course. It isn't really that hard to explain or understand, it's extraordinarily convenient, and it's essential for engaging with most quantum adjacent literature. I understand that it conceals the distinction between vector space and dual space a bit but it's really not that hard to get through. I may be biased because I learned the notation in week 2 of intro quantum, so I am curious if anyone with the opposite experience disagrees.
I think he just felt the students wouldn't be able to handle the linear algebra aspects of QM. Strange notion, given that all the students were seniors, and had all taken a linear algebra course from the math department.
Probably wanted less formalism overall.
Like when I took an E&M course in the EE department, and the professor insisted on teaching only the integral forms and not the differential forms of the Maxwell's equations (i.e. no divergence, curl, etc in the whole course).