California’s universities were considered too reactionary for academic careers

Evidence

Not only Horkheimer but Marcuse himself urged that he should go to New York so as to be at the disposal of MacIver, who had a particularly high opinion of him, and to bring the negotiations over departmental lectures by Institute associates to a successful conclusion. If he had any chances of an academic career at all, it would not be at the largely reactionary universities in California, but at Columbia, where he was the most respected member of the Institute after Neumann. — Rolf Wiggershaus, The Frankfurt School, 1230