They stated "...administrators to keep up with regulatory demands."

I wonder, however, if administrations just take on a life of their own and grow bounded only by available budget. It seems like this happens in the private sectors with layer upon layer of management.

That's certainly been my experience; management and bureaucracy will expand to fill any available budget unless constrained. Since management almost always runs the show, there's almost never constraint.

Hiring bodies to perform the administrative work required by law. Lots of compliance - title 9, etc at the federal level, plus more at the state level.

We have several teams of developers pushing out state-level regulatory updates to our software (and these updates are frequent and often done on short notice), plus more teams doing annual federal regulatory updates.

And again, I'm not claiming this is the largest contributor, only that it's one of many reasons (easy access to loans included as well).

A good example is the parallel legal and law enforcement systems on college campuses. In the past, you'd call the regular police and you'd take issues to the courts used by all other citizens outside the university. Now universities maintain their own law enforcement and farcical "justice" system. This stuff is not cheap to operate and comes with tons of overhead.