It's all a matter of taste. Personally, I don't think the landscape, three rocks(Iwagumi) and fish in the sky thing is natural looking at all. They can look nice though. On the other hand, an Amazon Biotope would consist of brown tinted water, driftwood, sand and tree leaves which might not look great in your living room. Dutch tanks look very minicured and geometric and have certain rules. My tanks doesn't follow any of these conventions. I grow the plants that I'm interested in, that are easy to trim and tend to resist algae. I'm in a Rotala collecting mood right now but, have lots of crypts, HM, Byxa, and Vals. Trying to balance out the textures and colors of the Rotalas.
I wouldn't let anybody tell you how your tank should look. Just have fun.