Another way to look at it is that Apple has to choose its trade-offs. The flagship feature of the iPad (3) is its display. The cost, in terms of trade-offs, is that it is thicker and heavier than the iPad 2 because that big gorgeous bright display requires so much more power. When designing anything, you pick one or two primary attributes and you compromise on everything else.
Couldn’t have said it any better.
Via (Daring Fireball)