I used to think the same way until I suffered neurological damage that affects the sensory nerves in my fingers. Holding down the shift key while I type some all-caps text, like "STUPID_SHOUTY_MACRO_NAME", is uncomfortable, so I now find the caps lock key useful. It would be nice to have it as a control key, but I would want some other way to activate the caps lock function. Maybe a double tap on the shift key, like on the iPhone keypad, would work.