Thing is, though, that I agree with you completely.
(If I remember right, "GFE" started out being used the way you and I see it -- not as a service given, but as a description of something that happens on occassion. So it wasn't that guys would say, "She's a 'GFE'", but rather they'd say [with a sense of wonder, as if they couldn't believe how lucky they got], "And then we had an hour of girlfriend sex." There was no expectation that this would happen for anyone else -- or even that it would be the same for the same john if he happened to see the same prostitute at a different time. Mindsets being what they are, however, "girlfriend sex" transmogrified into "GFE" transmogrified into a service rather than a description. And -- IMO -- it's been a source of misunderstanding and intellectual laziness, if not outright fraud, ever since.)