Actually, copy/paste makes a lot of sense. Having to frequently copy or move files from one place to another, I got used to ctrl-c or -x a file, then go to a different directory, and ctrl-v. The appeal, I think, is that I don't have to use the mouse (which employs a time-costly drag operation).
Dragging files into directories is also cognitively expensive - e.g. you have to make certain that you are dragging exactly into the right folder which can be about 15 pixels high, depending on what view you're using. It requires hand-eye coordination which becomes unnecessary with simple copy/paste operations.
BUT, for beginner users, I agree: users have a hard time grasping the concept of a copy/paste buffer anyway, and with files it gets abstracted one more level. For more advanced users, they use keyboard shortcuts, so the buttons don't really need to be there.
Dragging files into directories is also cognitively expensive - e.g. you have to make certain that you are dragging exactly into the right folder which can be about 15 pixels high, depending on what view you're using. It requires hand-eye coordination which becomes unnecessary with simple copy/paste operations.
BUT, for beginner users, I agree: users have a hard time grasping the concept of a copy/paste buffer anyway, and with files it gets abstracted one more level. For more advanced users, they use keyboard shortcuts, so the buttons don't really need to be there.