Oakes Spalding has revisited a question he asked on his blog a number of years ago regarding whether or not all weapons should do the same damage in games like Dungeons & Dragons. He’s taken the time to create a fairly comprehensive FAQ-style post that looks at some of the arguments against that type of rule (which was in the original game) and answers them. He then explains his rationale for how he implemented damage in his excellent Seven Voyages of Zylarthen and how he handled differentiated weapons.
I don’t agree with all of his conclusions and answers given, as there are some arguments given have some logical fallacies in them (such as increasing the number of damage dice distracts from the actual game being played, or having all weapons do the same damage increases diversity in the choice of weapons). However, as a designer and developer myself, I always appreciate being able to get behind the design decisions of how and why someone else chose to do things for a particular product.