[stetrain]

Because some people would pay the same price (or even more) as a MacBook Pro to have a great screen in a thinner, lighter laptop that shouldn't cost Apple that much more to make.

Like how the MacBook Air was originally a premium-priced product instead of an entry-level product in Apple's lineup.

[dannyw]

A new SKU (supply management, warehousing, logistics, employee training, etc) is pretty expensive at Apple scale.

The demand has to be there. And MacBook Pros are not that bulky.