One way to get more comments on your hubs is to read other hubs on similar topics and post meaningful comments there. If you leave an intelligent comment, the author of that hub is likely to take a look at your profile, read some of your hubs and leave a message in his/her turn.
Another thing is to get some exposure. As interesting as your hub may be, people have to see it for it to get some comments. You can let your friends know that you have published a new hub via email, facebook, etc
And, most important: write quality content. If people like what you write, if they find your information interesting and useful, they will give you some feedback.