@upper
I'm one of them. I never comment on stories. I don't read comments either -- I've had them turned off since the feature was introduced.
In large part, that's a reaction to comments on lit. There, there are too many comments that bash stories for superficial reasons. For example, almost any cheating wife story in which the husband even considers reconciliation will have several comments like "1* cuck shit".
Feel free to be part of the resistance to such silliness.
I only occasionally comment publicly, but I still do it. I send authors notes far more frequently. Some authors, like me, want to know when they messed up (missed a word, seriously screwed up the punctuation, that sort of stuff), while others are outright hostile to such comments. I try not to bother them.
Even with those authors, though, if a story catches my interest I try to let them know why, maybe including part of what I did/didn't like. I also tend to ask questions when I don't understand something (e.g. the British school system!)
I'm sure there are plenty of authors like me, who aren't trying to make money from our stories, but are just trying to entertain people in some, small way. If I didn't care about others seeing/enjoying my stories, I'd never put them out there, or even type them up โ I can already enjoy them in my own head, after all. A little encouragement helps make the extra effort to publish them worth it.