In years since the original study, the general finding that “There are order-of-magnitude differences among programmers” has been confirmed by many other studies of professional programmers (Curtis 1981, Mills 1983, DeMarco and Lister 1985, Curtis et al. 1986, Card 1987, Boehm and Papaccio 1988, Valett and McGarry 1989, Boehm et al 2000).
I think these orders of magnitude are not present in between people in many jobs. And I think people’s ability to correctly access who are orders of magnitude better is often faulty. But my experience leads me to believe the difference between exceptional software developers and average (not even below average) is very high. High enough that large increases in pay (say tripling would be sensible). Also accommodating their desires is sensible: freedom from dealing with pointy haired bosses and eliminating other such de-motivators.
While salespeople seen as successful can often be rewarded very well, exceptional software developers rarely are. Most managers don’t seem to be able to grasp that software development is a rare field where such orders of magnitude differences are somewhat common (not one in a million, maybe one in a thousand for a random guess). There are other fields where this is true but most for most fields I do not think this is the case.
In many fields interruptions are costly (and multi-taking is wasteful). In software development those interruptions are often much more costly than in other fields. Peopleware: Productive Projects and Teams is an excellent book on managing software development.