I prefer window seats specifically because they are up against a wall, and I know I have an armrest to myself. If that's where I end up, I am more likely to just close the window shade, particularly if I am jetlagged and need sleep.
However, I had status on United for a while and throughout that whole time did not have to pay any extra fees for that "window" seat. If the airlines are up-charging for window seats, then they better have windows, otherwise they should call them something else.