Academic units need the ability to select (and fund) the applications and even devices they will use in their specific teaching and learning environments. Their students, faculty and administrators are better served if these can match their specific academic and departmental needs.
One-size-fits-all is seldom, if ever, the best approach in academia. It doesn’t work with pedagogy, it doesn’t work with classroom or lab spaces and it doesn’t work with textbooks or content — so why would it work with IT? Some academic programs, for example, are Mac-centric while many others are fine with Windows machines and applications. Some academic programs (or practitioners) gravitate to open source offerings while others eschew them. Both groups have their reasons and both seem sound, in situ.