This debate is as old as Rosity itself, although it usually occurs over in the Poser forum/gallery, & it can get quite nasty over there too (good entertainment if you've got nothing better to do).

Actually, regarding the viewing, but not commenting I do agree with has been posted somewhere in these forums before. Something along the lines of: how many times does an image need the same compliment underneath it?
I'll comment if I see an image early enough or if there is something specific that I really like. I often vote as well, but don't say so. It would be good if there was an extra button on an image page that would add your name to a list of people who like the image - sort of like the 'Favourite Image button, but without adding the image to your homepage (or I'd have nothing else, but images I like).