The real reason college costs so much is that the price of all services provided by people with doctorate Or professional degrees has risen. The cost of higher education has risen at the same rate as the cost of dentist services and legal services. See: https://image.slidesharecdn.com/disruptiveinnovationinhigher... Archibald and Feldman, 2010
The reason the cost of all services provided by people with doctorate or professional degrees has risen is complicated and could arise from many factors. For instance, it could be that there’s more industry demand for highly educated labor.
The rise in college costs relates primarily to overall changes in labor costs, not to anything wrong with the education system in particular.