Stuart, I hear where you're coming from.
It was years before I got more than "good picture" for stuff I posted.
I guess people are scared of offending if they offer advice, as Asi said earlier.
Personally, I don't go look at every picture that is posted, unless it's an object I have an interest in. And finding an original comment to make on each one is impossible. If it's a "good image" I'll say so, if it's a "great image", that is exactly what I mean.