Code sure is important, but just part of what you offer, a solution. Every individual and business has different needs and constraints, where you might end up using a lot of common code, but the solution is different. By giving away your code you can only benefit, not harm yourself. You get all the credibility, goodwill and even get back a lot of code back from the community.

Does goodwill and more code pay your bills? Not meaning to be money-minded, but some payback for your effort is almost your right as a programmer/developer!