After 33 years of entertaining millions and redefining late-night television, David Letterman is retiring. And while, like the many celebrity guests who have been bidding him farewell, I too appreciate him as a funny, smart, silly and creative talent, I want to offer a curmudgeonly and less generous look at his legacy. In fact, I wonder if his contribution to pop culture might have been, well, too curmudgeonly and ungenerous. There are plenty of ways Letterman took late-night comedy to…  [more]