It's nominally true because many programmers have zero or lower productivity, sometimes due to no fault of their own. If you work on a project for three years, and then it gets canceled, you could say your work had no economic value because it never got in front of customers. If some PHP hack manages to pound something out in a month that brings in $100,000 of business, he looks like a hero, no matter how bad the code is.
In my view, superproductivity is about alignment with your environment. If you work for 12 months a year, but spend 3 of them on side projects that go nowhere, spend 3 months being a sysadmin, and then waste another 5 months on reworking a GUI, there goes about 90% of your productivity.
The "Mythical Man Month" says that about 20% of the time on a software project is spend coding, the rest is requirements work, testing and that kind of stuff. A superprogrammer with supertools might be able to do that in time that approaches zero asymptotically, but unless you can get rid of the other 80%, project cost and time don't get much worse, even in comparison with a coder who is half as productive as average.
The moral? If you want to look like a genius, find some place where (i) requirement work takes little time (and wastes little time downstream with changes) and (ii) testing, deployment and all that is minimal.