I think I mentioned before somewhere, that my job takes me traveling all over the world. I have to carry my work laptop with me, plus I opt to carry my personal laptop and an iPad. It's a hassle. After a while you start feeling pain on your shoulders and back. I'm always looking to have thinner options for the personal laptop and iPad to minimize this (IPad Air 2 is pretty good at this btw).
Thinner, lighter products are not necessary, but a nice convenience that require engineering breakthroughs to achieve. Ideally for me, in 20 years I would be carrying a device as thin as a piece of paper, weighing about as much, with great power and no ports

(I know, but a man can dream). I view this convenience as a luxury.
Granted, this may not resonate with those that don't take their laptops much outside the house, except for the trip here and there to the coffee shop. But, once you need it like I do, it's a huge thing.