But they knew customers would want more battery life than 1 hour. So rather than make it as thin as possible, they figure out: what is the best battery life:heft ratio?
That is what I was questioning in my OP: is this ratio, in the eyes of Apple, out of sync with this ratio in the eyes of the consumers?
Obviously, Apple knows how to build products. But it would be naive to assume that Apple always strikes this balance perfectly. I'm just suggesting that they may be pushing slightly more towards design over function.