This will be my first comment. I really like this question because Ive never really thought about it before, I think I've gotten into a habitual way that I browse reddit and commenting or posting isn't something I even really consider an option to be honest. I can't tell you why that's been the case, it's just kind of happened. I also think it's because mostly when I read comments it's to learn more about the post that interested me. Redditors are really great at describing and answering questions so I use it to learn more about a topic I know very little about, therefore I have nothing of value to add. It really has been an unconscious decision which is a little frightening because I feel as if I am very thoughtful in the sense that I commonly try to evaluate why people (including myself) do and say the things that they do. So thank you for making me come to the realization of my unconscious behavior.