Wilder embraced complex characters, especially Protagonists. Think about it. Baxter is essentially acting as a kind of pimp in that he willingly facilitates his company overlords in their sexual trysts. It is, as the Catholic church would say, a sin of "omission" in that he's not actively setting up the woman with the guy, but it is a "sin" nontheless. And Baxter is the character we are supposed to be rooting for. Yet, he and Diamond write a script ... and Jack Lemmon inhabits the role ... in such a way that we are along for the ride on Baxter's side.