'Cos you can buy 3 for the price of one and still have 95% of the functionality.
Don'r get me wrong - I'd
love a Macbook Air, but it really is vastly overpriced for what it does, unless you're buying it for bragging rights.
Not having a LAN socket (yes, I know you can buy a dongle) is a big nono for me.
There are several ultralightweights around that aren't as pretty but do the same job for much less.
Mac