There is no such thing as a "Mac XXXX killer". Apple's prestige comes from their ability to make products that are a fashion statement, which are bought up by people who either would've never amounted to anything if they didn't inherit their money, or else people with low self esteem who think Apple products will make them look cool.
To those ends, it wouldn't matter how much better a non-Apple product was. Besides "thin" is not a useful feature, a Macbook Air, like an iPad, is not a real computer used for real work, it's just an expensive way of crying out for attention.