We all struggle with the "why" question. It has taken me a couple years to get a following, very small it may be, but I do get several views and comments. But, as a daily gallery peruser, your thumbnails are not "eye grabbers". In my opinion. It also seems, that if you just reduce the entire image to a thumbnail, people look at your thumbnail and move on. That's just my experience. I try and comment on people's work that stirkes me as excellent, both to encourage them, and hopes of them checking out my gallery and leaving comments.