Speaking of comic art, it is hard to find anything that is truly great or groundbreaking or revolutionary. Most of it served it purpose. It wasn't for expression, or artistic ability, or to blaze a path for future artists. It was to tell a story and to make a buck. It was production art that was done on a timeline.
It really isn't about the art itself in most instances. It is about the nostalgia. That view might seem like a cop-out but it is the truth. I think that is why people have a hard time slamming other people's pieces. I have some art that just looks horrible but it makes me smile every time I see it. Do I want others to slam it. No. Out of respect, we don't slam others' pieces.