As you said, he never could push the R6 to it's potential (the goddamned bike has 108hp!). I'm sure he would have got his money's worth out of a smaller sport bike, but he loved the feel and style of the R6. It fit him. He was considering an R1, but felt it was overkill.
People buy R1's for the same reason that people buy a Lamborghini. Do you think those dudes owning Gallardos are driving them to their full potential? I don't think so. They own them for their own reasons.. styling, lifelong dream, status symbol etc. The same can be said about super bikes like Hayabusas and Ducati 999R's. Badass bikes that all of us would no doubt happily take if one were given to us (myself included. I'd LOVE a Ducati).