In my belief, people do not learn how to use graphical user interfaces by way of metaphor. If we accept that this is so, then we also have to accept that learning new meanings for words is a coping device for dealing with a metaphor that doesn't work. Since the use of the metaphor is supposed to ease the cognitive load on the user, then it is clearly a reverse of the desired situation. I believe Donald Norman has captured the essence of this problem. The real problem with the interface is that it is an interface.
Interface gets in the way.
I don't want to focus my energies on an interface. I want to focus on the job. My tool should be just something that aids, something that does not get in the way, and above all, something that does not attract attention and energy to itself. I want to think of myself as doing my job. Therefore, it would seem to be a simple step to then realise that many successful productivity tools are successful despite their metaphor.