Isn't that what 7A/8F are for? (or 9A/10F on the 737-800), so people get the window space without the actual window? Or eye masks.
It used to annoy me a lot, but I've sort of given up being annoyed. It mostly bothers me on takeoff/landing when people close the shades; the rest of the flight I feel like they can do what they want, even if it bothers me.