^ this.
It's absolutely better to spend the time to make a well-thought out game rather than rushing to publication.
But, there's an awful lot of people who post lengthy descriptions of how incredibly detailed their thousands-of-pages epic is going to be, and spend a lot of time debating in forums about every idea and character and sidequest they plan to add to it-- only to publish a five page, choiceless "preview" after about two weeks, then abandon the project when they realize how much work it's actually going to be, or when they get a "better idea," or they just lose interest.
PS: I'd say don't let the fact that there's already an amazing storygame in your genre stop you from utilizing the theme.