Apple and many tech companies are a world where association is everything. “I work at Palantir” means a lot. “I work at Uber” at the moment may be both positive and negative. The academic world is not like this at all. Paper count is everything. Churn them out with all the power you have. Most universities allow their teachers to take sabbaticals on the hope (and sometimes mandate) that they will publish. So Apple was not going to find many academic researchers who were okay with not being allowed to interact in the same way with their community.