Something which really grinds my gears is when software has non-rebindable hotkeys. Why are keybinds hardcoded? We can change our controls in games from WASD to ESDF. Why can't we change our copy key in Windows from CTRL+C to CTRL+L, without using 3rd party software?
Having written my own applications on occasion, I know this isn't that difficult. So why is it so uncommon?