The mac is extremely good in being bad in this. CMD+Control+Q locks the computer. Incredibly useful for office places, where you are not alone. Not quite hitting that Control-key though, and your app quits.
I'm guessing people who design/choose shortcuts like to group similar/related action shortcuts near each other like copy/paste. I am constantly hitting command+c when meaning to command+v still to this day! Some apps will annoyingly copy a blank space (or clear your clipboard) if your cursor is in an input/textarea but you are not highlighting anything. Chrome does not do that, on Chrome if you do not have something highlighted it will not copy it.