From Daring Fireball:

When ‘Smart’ Cut/Copy/Paste Attacks. “Once software starts down this path of guessing what it is the user is trying to do, and then doing something special based on that guess, it must guess correctly nearly every time, because the times when it guesses wrong are so annoying that they far outweigh the extra convenience of the times when it guesses right.”

The other people he could have called out were the geniuses at Palm (and others) who decided to use modifier-P for Paste rather than sticking with the de facto standard.