First, no one really knows what are storyworlds. Not even it's creator Chris Crawford. So if my understanding is right. Storyworlds are like interactive fiction but with less interactivity with sprinkles of decision making. They have a big focus on content. That's not a problem. Actually this provoke a 'insert here' effect. If less interactivity better content.
However, this assumes that the storyworld subgenre, don't consider systems content. As I said is not a problem in the storyworld subgenre. It's a problem if you want to change the industry. In one if Chris Crawford seminars he says. "I want to build a community". I ask how can you build a community if the element you are offering is less than other more well known communities?