When does a work of Theatre Art Fail?

At the University of New Hampshire the arts department (mainly the Theatre and Dance but thte others have chipped in too) have had an ongoing discussion this year about the relationship between art and democracy.  A Professor of mine brought up the point that whenever the University puts on a show that only entertains and does not challenge the veiwer to think, the University fails.

I have taken it one step further to say that any play that only entertains, fails.  If somthing is meant only to keep you occupied for the amount of time it is on and doesn't challenege you to think, it was a waste of time you can't have back.

What do you people think?