There's a discussion thread in full tilt on one of my local teaching newsgroups at Strathclyde. One of the contentious issues is the fact that few staff seem to interact with their students. The answer is quite simple, most universities operate A PERVERTED ACADEMIC REWARD SYSTEM found on the Tomorrow's Professor Postings website:

"The more time faculty spend on teaching, including hours in the classroom, the lower the pay. This relationship holds true for all types of institutions except for the percentage of time spent on teaching for faculty in liberal arts colleges. Conversely, the more time spent on research and the greater scholarly productivity, the greater the pay ... These results support the view that teaching activity and productivity are at best neutral factors in pay, at worst negative predictors of pay... If research and scholarship are valued more highly in promotion and tenure, taking time away from research to devote to teaching may adversely affect faculty careers."

BTW, the Tomorrow's Professor Postings website is a valuable source of opinions and facts.