Many good comments here. Although, I think I am in a minority when I reassert my claim that ratings are irrelevant. If YOU like or dislike a story, how does your rating help ME decide if I am going to like it or if I should read it? Are your tastes the same as mine?
If an author gets a good or bad rating, what does that mean? That the reader didn't like the story or didn't like the subject or didn't like the editing or didn't like the pacing or didn't like the settings or didn't like the protagonist or didn't like the...? A rating is irrelevant, it doesn't convey any meaning.
If a reader were to leave a comment or commentary, then we have something more useful. They can say what they did or didn't like and why.
Making a comment does not mean leaving a snide remark or nasty insult, - that would simply be an act of bullying. If readers and authors want true ratings and reviews, then comments and suggestions are the only way to accurately convey meaning. A reader can say what appealed to them, or didn't, and why. Editing and other construction faux pas can also be illuminated or discussed. A simple like or dislike, to me, as a reader and as a writer is meaningless, I don't care if you liked or disliked it - WHY you liked or disliked it is what I care about.
If my story lacks focus or wonders all over the place while trying to make a point, then say so. There is no shame is being honest - and no learning without it. I'll never get better if nobody tells me to get to the point or quit making asides to my asides. Grammar and punctuation are somewhat straight forward, but can also be subjective in places - did I use punctuation in a way that helped or hurt? Was my grammar sucky or was I eloquent?
We all start as beginners. Getting better means we learned better ways of doing what we do. We learn when someone gives us feedback - constructive feedback. Even if you hated what I wrote or wrote about, did I write it well? Was there a more palatable way to convey the thesis of the story? Even if you thought my story PROVED I must be a worthless human being, then I must have presented the proof well - what made it seem well done?
A plus, minus, star, moon, or thumb up/down is worthless, it doesn't tell me or readers a single thing worth knowing. Just because this or that story has a 42-star rating doesn't mean a darn thing to me. I hate stories in that genre so I give it a half star. I hate the way the writer writes so I give it a thumb down. Who cares what I think? WHY is far more important - and that requires words.
I've seen millions of posts and stories here with ratings on them that I thought were completely opposite of the way I would have rated them. There are highly rated authors here who I haven't been able to slog through even a single one of their stories. There are unrated authors here who have stories that I have re-read several times. A synopsis or a review will do a heck of a lot more for me than a rating.