I'm buying an Olympus Tough TG-3, as the D30 was a total dissapointment.
Surely creating a naff product doesn't cost much less than creating a good (not great, but good) product?
I'm guessing a bean counter decided they should save a few bucks by using an existing lens to keep costs down and get rid of excess stock (all their point & shoots seemed to start at 28mm a few years ago, then they moved to 24mm, so it was disappointing when the 'new' D30 didn't get the same treatment). I can see no other reason for an underwater camera to have such a slow lens other than interfering bean counters - one would normally spec a fast lens in this category.
I too didn't buy one because of the lens (spent the money on beer and women instead). Better camera phones (water resistance & IQ & handling & responsiveness) mean I'm probably not likely to buy a point n shoot in this category at all now. Instead I'm looking at Go-Pro type cameras (surprised Canon didn't target that segment too).