I've never understood the ridiculous "Look at all that Key Item space not getting used!" argument. Does nobody stop to think and realize that the number of Key Item slots you see depends entirely on how expanded your inventory settings are? As someone that sets it to normal, there really aren't all that many slots.

Plus, y'know, what was already said, about none of them actually being "items" so much as flags that the game recognizes you should be able to use the special thing or progress a quest or whatever.