I suspect, compared to other OSes of the era (Multics, MVS..), Unix doesn't require too much centralized control of (timeshared) operating system resources; for example the security model is extremely simple. So it was readily adopted in academia, because of this perceived user freedom (you just need a shell and you're good to go), and from there it spread to the industry.
So C and FORTRAN didn't came out of the academia, but were more widely adopted by it, which influenced later generations of students.
That also made UNIX an ideal teaching device for OS programming classes versus the toy OSes developed by students.
Well, until AT&T forbade the circulation of UNIX V6 commented book.
https://en.wikipedia.org/wiki/Lions%27_Commentary_on_UNIX_6t...
Other than it was probably great having an OS where LISP had the spotlight alongside Assembly.