I so agree with you. When I first started reading here, I did just that, but I found I needed to tell how much I enjoyed reading the stories I read. That's when I first made an account here. I could log in using my Facebook account, which allowed me to leave comments. Ever since that day I've commented on every story I read. Personal posts as well.
Sadly though my comments rarely go beyond the omg variety, although I'm working on that lately.
Safe to say I love all you writers for writing great stories, or for sharing bits of your personal life with us. I will continue reading and commenting.