I've been thinking these same thoughts. I recently switched from Schwalbe Marathons with kevlar belt to Schwalbe Kojak slicks. I switched because I was getting too many flats in the so-called flat-resistant Marathons, but I've been delighted by the ease of the new slicks, the first I've ever had, and so far anyway no flats. I'm a slick convert now.
Another thing I've been thinking (I even made a thread on this) is that narrow tires might be more flat resistant than wider tires, especially if the thickness of the rubber is the same, since the wider tires have a greater chance of running over a piece of glass.
So here's my plan for the best bike tire: very narrow high pressure slick tire with strong thick rubber. Who makes that?