> and more incentive to do research

Correct me if I'm wrong, but I was under the impression that the entire point of tenure was so that professors who have proven their worth have the freedom to do the (perhaps controversial) research that they want to without fear of retribution from their employer.

Edit: And now that I think about it, the point is also to prevent "dead weight" from being fired. Because it'd be easy to classify a professor as dead weight who is simply working on something unpopular, or contrary to consensus.