Kindle Paperwhite is the most-advanced e-reader ever constructed with 62% more pixels and 25% increased contrast, a patented built-in front light for reading in all lighting conditions, extra-long battery life, and a thin and light design.
If profits thin out as the only real success comes from extra-cheap devices like the Nexus 7, there's fewer opportunities to gamble on technology research that might not pan out.
As evidenced by the photo, the thin-as-hell MacBook has no optical drive and sports an extra wide trackpad and button, which makes the whole thing look pretty goofy.