As a reader, I don't use ratings to identify a good read. They're entirely subjective, and don't tell me anything about the story. I look at the summary, and if that catches my eye but doesn't entirely sell me, I look at reviews. I've seen FAR too many stories with huge numbers of 5-star ratings that were written without regard to spelling, punctuation, or the basic rules of grammar. I'm not trying to be overly stuffy, but I get distracted by a high level of errors, and it takes me out of the story to the point where I lose interest.
As a writer, ratings don't help me improve. If they're high, I have no idea what people liked most. If they're low, I have no idea what needs to be improved. They serve no purpose for me other than to make me wonder what readers actually thought about the story, but weren't willing to say. Given that I can second-guess myself into a state of literary paralysis all on my own, I don't really need any more encouragement to be afraid to post anything.