About the ratings: I just checked today and new stories were posted no more then two hours ago and lo and behold half of them were already rated!
If rating is all that important you can always check Highest Rated stories.
And yes you can actually review the story and not rate it. Write to author. They adore it! (Some will actually continue or drastically alter the story in response to just ONE email!) And you can always edit your review and CHANGE your rating. (And yes I HATE reviewing unfinished tales, but, what the hell …)

But all this does not answer the basic question: is the general quality of writing deteriorating? Agreed, older tales are familiar, almost 'old friends', many are ground breaking, but still: Brand new writers deserve a chance!
(And, just a reminder - some of the stories now considered classic were very badly rated when they appeared.)