Well, I'll be the one to own up...I'm the type who clicks on the topics and doesn't comment.
For the most part it's because I'm unbelievably lazy (I actually prefer to think of it as an extreme form of energy efficiency) and the best I can muster at times is a mouse click. Moving both my hands to the keyboard just seems like an effort a lot of the time, so I don't do it. Sorry about that.
Sometimes, though, when I can be bothered to type, I just don't have anything to contribute. If it's someone asking to comment/critique a tank setup, often times, I might not like it, so I keep shtum because I'm not in the business of hurting someones feelings if they've put a huge amount of effort into getting their tank the way they like it.
For all other reasons I don't comment, see reason number 1...
