Uh.. you haven't priced a decent bike recently, have you? My present bike runs about $1,600 CDN and the one I will be getting in the spring will be about $3000USD/$3500CDN. That's actually not too expensive. My ideal bike would put it around $6,000CDN. No chump change there. It really isn't the Walmart-type store bought bikes that would be of concern but the specialized bikes bought at a LBS (Local Bike Shop) made for a specific purpose (in my case long distance 3rd world, tough terrain touring). In others, and many of the ones on the bike forums I visit, it's racing, randonneuring and MTBing. Serious adventure nuts who want something that will truly last, be a good ride and worth it. Kryptonite used to have this warranty where if the bike was stolen while using one of their U-locks they'd replace the cost of the bike. Kryptonite is the single largest bike lock manufacturer out there (I don't know the exact numbers but given the response at this thread, I'd say it's a lot) and they have the most to lose.

So in actual fact, many of the things held by a Kryptonite can be worth as much if not more than what a Kensington would hold and more public (how many bikes do you see locked up in an office versus on the street?).