Licensing also plays a big role in this. Officially licensed rulesets almost always outperform community rulesets by a large margin. Most RPGs for super hero or other film based items are already licensed out to a tabletop RPG publisher. Getting a license with the publisher for these would mean that the proceeds would now need to split to an additional party and the contracts become more and more complicated. As an example, we have official licenses with Green Ronin but only for their first party game systems and not for stuff that they had to license from someone else - A Song of Ice and Fire , DC Comics based content, etc. The same thing limits the ability to get any sort of official Star Wars RPG support.