Unfortunately, fiction often falls victim to the "Usenet nod syndrome." People read it and nod, but they don't feel like saying anything, so they don't reply. Also, some people are uncomfortable with posting honest criticism (as opposed to "Yay! Great story! Write more please!" fluff), and some authors are uncomfortable with receiving anything but praise.
This can be very discouraging to us Volatile Creative Types, because the worst reaction, IMO, is no reaction. If a story has a high hit count but no replies, it appears as if the story simply didn't interest the reader at all.
My only suggestion would be to post a note at the beginning of the story stating that you're open to reader feedback; comments and criticism welcome! But only if you mean that. (I personally love a serious, critical review; it shows me where my strong and weak points are and where I can improve.)