At the end of the day, I make less than minimum wage teaching these students. I'm lucky that I have another job that supports me.
Colleges and Universities are not lean organizations. My department has significant amounts of overhead - people that in some cases work full time doing administrivia or extra paperwork and they require a salary. The buildings and labs also require upkeep and technology has a fairly high turnover cost. Add in the racket that is software + books and things add up quickly.
I'd estimate that my department has almost a 1 to 1 back office staff to professor ratio - simply due to the lack of automation (and no desire to automate) many portions of the work that is done at the school. Many of the back office staff are full time and they receive a regular salary rather than a flat fee per student.