If by "graft" is meant hard work (rather than some kind of corruption), I too cannot understand the link in this country between hard work and reward. Without going into any detail, or piling up examples of various kinds of work at widely differing rates of pay, I'd just use the observation that a GP, or a Practice Nurse, does real work of more genuine value in one shift than some highly paid people do in their entire "working" lives. As one particularly unpleasant politician put it a generation back, though his targets were different, they would never be missed.