This is because you could review only the games you have purchased.
Even on Amazon, you could review the products you purchased.
However, you could start reading any story on the Scribble Hub anytime you wish.
I didn't even encounter stubbed stories, not to mention there isn't the ranking list that forces to notice the novels in certain order (there is ranked per tag, yes, but it doesn't order stories unless you try really really hard, rather than being default more of view)
If the Scribble Hub worked on the Steam ranking model, the stories would stabilize on the certain value relatively quickly.
Not to mention, the Scribble Hub algorithm isn't rating based as on the Roadkill Route, which means all rating would be more informative, and clearly explained, instead of being 90% anonymous.