Generally, the 'Story Comments' are for readers to discuss the story amongst themselves, not for them to offer advice to the author, although I, like several other authors, often respond to topics raised.
Most often, if someone wants to raise an issue (like a factual error in a story, or typos), they'll respond with a Personal Message, so only the author sees it.
Both need to be turned of for each story, though the 'Personal Messages' establish a default once set.
As for story comments, I have two recent stories in the same series, one got a TON of comments, the second started off well, but the comments soon ceased.
Sometimes, authors are merely left scratching their heads over why something falls flat. Does the lack of comment mean there's nothing to object to, or that the story failed to inspire and challenge readers, essentially, a snooze-fest? There are no easy answers to those questions.
Oddly, though, the first story got higher ratings on SOL, while the second story got higher ratings on FS, so clearly, much of my story issues are based on the desires of the people reading the story, rather than on the story themselves. I hope that provides some comfort that it's not always about the story.