I think people are just parroting soundbites they hear like "the number of administrators keep growing and are causing the tuition increases." In reality, what's happening is way too complex to be described in a single or even a few sentences.

The role of universities is expanding. Should universities play a role in the local communities? Should they do research? Should they perform outreach to improve diversity? Should they accommodate all facets of student life? Should they have sports? Should they teach courses to non-students? Should they fundraise? Should they support extracurriculars and provide leadership opportunities? Should they offer financial aid? Should they manage real estate and parking? Should they resolve disputes among faculty and students and departments? Should they invest their endowment? Should they support alumni? Basically, each of these needs a team of people to manage.