That's because Dan Dennett is a p-zombie. He's never experienced consciousness, so he can't fathom what it is. Same goes for a number of other eliminative materialists such as the Churchlands, Graziano, Blackmore, etc

Interestingly, Richard Dawkins the mega-reductionist-Uber-atheist is not one, and neither is Kurzweil, who believes in computationalism (functionalism); you'd be hard pressed to find it in his books, but he slipped and all but admitted that consciousness is something that transcends reductionism in a reply he wrote to Jaron Lanier's One Half A Manifesto in the early 2000s

It would help the discussion if we could steal the terminology back, because it's been zombified by Dennett (continuing what his mentor Ryle started) and his ilk. I think we ought to distinguish "Dennettian Consciousness" (where 'consciousness' is just a convenient, abstract label for the bag of tricks the brain can perform) and "Chalmerian Consciousness" (the real kind of consciousness, the reduction-transcending-ineffable, for people who believe in the Hard Problem)