Being able to cut and paste in the terminal without thinking about it too much was one of my favourite features of Mac OS X, but it's nonsense to claim it's because of Apple's Interface Guidlines. It was just an unlucky coincidence that Apple avoided by chance.
Meanwhile the shortcut command for quit is right next to the key to close a window (at least in Qwerty). That's kind of stupid, but lets not go building any grand theories to confirm our biases just based on that factoid.
"It was just an unlucky coincidence that Apple avoided by chance."
The fact that they were not specifically thinking of the terminal (which you are assuming) does not mean that it was purely by chance. That's a non sequitur.
Meanwhile the shortcut command for quit is right next to the key to close a window (at least in Qwerty). That's kind of stupid, but lets not go building any grand theories to confirm our biases just based on that factoid.