[Confusion]

I think you are right it helps explain NIH, but I don't think it justifies it. In the article, Naur says:

  I shall use the word programming to denote the whole 
  activity of design and implementation of programmed 
  solutions. 

So 'programming' is not just 'producing code', but also everything leading up to that. It is very well possible to design a solution for your specific problem and then conclude somebody already implemented (parts of) it for you. You get NIH if you need to implement (part of) the code to discover how you can use software to solve a problem and subsequently cannot let go of your code. So there are two opportunities to get rid of NIH: 1) become sufficiently proficient that you can design software without needing to write lots of it already and 2) be able and allowed to throw your code away.