Ego. In my experience, most problems come down to ego.
Consider the Assistant Deputy VP for Administrative Affairs who just got sold an official $20M "Enterprise Scale" solution for course registration that worked about as well as healthcare.gov, and a kid comes along and in a couple of weekends, makes something that works better and has more features.
Now the 'unofficial' solution is getting more and more popular and your gold-plated turd of a system that you staked millions of dollars of Official University Budget on is getting mocked mercilessly by the student body.
What do you do?