<p>One reason for the emphasis on research is the tenure system. A college or university will decide whether or not to grant tenure when an assistant professor is perhaps 31 or 32 years old. If granted tenure, that professor might be teaching for another 35 or 40 years. What might be state of the art to teach today will probably be passe, outmoded or even contradicted 35 years from now. The expectation is that a professor who is continually doing research will keep up with his/her field, so that when she/he is teaching freshman English/History/Philosophy/Math/Chemistry or whatever 35 years from now it will be up-to-date. Granted that it is harder to measure research progress in Philosophy or English Lit than it might be in Chemistry.</p>
<p>Plus, the whole PhD system is set up to produce researchers. Often there is short shrift given to teaching in grad programs. I remember in my PhD program the minimum requirement was that you TA for 1 quarter, hardly in itself likely to make you a fabulous teacher. The PhD is designed to show that you can do and have done original research in your field. It seems unlikely that you will be able to take people who have been focusing on doing original research for the last 3,4 or 5 years and say once they become university professors that research doesn’t matter.</p>
<p>Not that I would necessarily agree that the current system is optimal or even sustainable, but it has its own internal logic.</p>