My rant - why don’t readers want to leave comments?

I am wondering why there are so few comments left on this site. My friend Lajien has been posting a story here weekly (Abrupt Change) and no one wants to leave him any comments here. This lack of feedback has him considering to abandon his stories here, since it seems to him that no one is interested in them. How can we change this? It seems only a handful of readers leave comments. How can we encourage people to leave more of them?