[PeterisP]

But the results are usable by others, in most fields of science the code is not part of these results and is not needed to enjoy, use and build upon the research results.

The only case where the code would be used (which is a valid reason why it should be available somehow) is to assert that your particular results are flawed or fraudulent; otherwise the quality of the code (or its availability, or even existence - perhaps you could have had a bunch of people do all of it on paper without any code) is simply irrelevant if you want your results to be usable by others.

[BeetleB]

> The only case where the code would be used (which is a valid reason why it should be available somehow) is to assert that your particular results are flawed or fraudulent;

Not true. Code is often used and reused to churn out a lot more results than the initial paper. A flaw in the code doesn't just show one paper/result as problematic. It can show a large chunk of a researcher's work in his area of expertise to be problematic.