I don't know where the misconception comes from that university professors are overpaid (no, I am not a professor, but I am employed as a university administrator).
Bear in mind that the average Assistant Professor has invested 5-7 years in graduate school, and in many instances, has another 1-4 years working as a post-doc. And for all they have invested in their education, their median salary is $59K a year.
http://en.wikipedia.org/wiki/Professors_in_the_United_States
The 30% of faculty whose academic achievement eventually earns them the rank of Full Professor (typically late in their careers, with a median age of 55), draw an average salary under $100K/yr.
Obviously, the salaries of the best and brightest at major universities are greater, but when you consider the brutal competition for jobs, and compare faculty salaries with positions requiring similar education in the private sector, you have to ask why anyone would ever want to go into academia.