That's why I am most amazed they left it out. My original MBA (my first Mac) had the backlit keyboard and it made me think 'Apple products stand out from PCs! What class!'. Without the backlight, they lose that edge ('cool factor').
A calculated risk on Apple's part?
There's quite a bit more to their "cool class factor" than a backlit keyboard. I can assure you that many people that buy Macs for the first time pay more attention to the build quality (which is second to none in their class), the screen quality (which is better than the majority on the market) and the large multi-touch glass trackpad. Most newbies don't even know that they are getting or losing a backlit keyboard upon purchase unless it's been pointed out. It's certainly not one of the features that can be demoed at the Apple store. Calculated risk? How so? They are selling a lot of these and for the most part people are very satisfied and the reviews have been great. I think they know what they are doing or they wouldn't have billions in the bank. You're leaving out so much about the Macbooks that make them stand out, you're just upset about a keyboard that doesn't light up and frankly you need to get over it.
I really don't think that the backlit keyboard makes sense for a BTO option. It would be something that they would do to all or to none. I don't believe it would really cost them that much more to put it in all of the next generation MBAs.
You're forgetting that Apple doesn't "half-ass" how they implement features. It wouldn't be just a backlit keyboard, they would also have to implement the ambient light sensor for the keyboard and the screen as they are all tied together as one feature. It would cost more than you think, but you're looking at it as some small little backlight the have to install and there's more to it than that.
Also, please use multiquote rather than double post, the mods will come down on you about it, it's against forum rules.