Ah, the elusive comments section. Much underused. Maybe people can't work out how to leave a comment (although spammers seem to manage). It can't be because there is nothing worth commenting on, can it?
Often perhaps, that is exactly the case. Unless you've written a piece that sparks debate or challenges concepts and viewpoints, perhaps it just doesn't require a comment. Someone may have enjoyed your post, and even found something new because of it, but just not been compelled to tell you about it. Sometimes you have to log in to leave a comment, or decipher an indecipherable captcha. If it is hard work in the slightest, then only the most conscientious reader will bother.
I've read that a good way to encourage comments is to start a dialogue with your readers; ask questions, ask for their opinion or ideas. If the post is being read by the right people then hopefully someone will take the time to write. If they do, it is a good idea to reply individually to them, starting a conversation perhaps, and hopefully encouraging them to return.