@yoyoyaya Thank you so much for drawing attention to this interview. As a guitarist and record maker myself (as well as a SD fan), I found it fascinating in ways that most listeners might not. I learned more about Steely Dan than I'd ever learned before, too. I'd never heard about Walter Becker kicking over Denny's Kustom amp during a performance--that must have been hysterical (and probably well-deserved--if you've ever played guitar through an old Kustom amp; I'm not surprised Kustom had to give them away to bands).
I agree with @frogman that there's nothing wrong with Denny. He just strikes me as a mellow, low-key kind of guy, unlike many more flamboyant musicians. He succinctly nailed his contribution as playing jazz guitar in a rock context.