I have talked about this with my friends before, and for me everything pretty much looks like plate. Or the plate looks like cloth, because there's really no distinction. Take the paladin "plate" robes as an example. Don't get me wrong, I prefer wearing a dress on any character that's able to, but I just don't see a difference. Also leather/mail looks like plate.
I have wondered if it's just too difficult make the material textures look more different because of the way they are "glued" on top of the character model? I mean cloth pieces should have more of a flow to them compared to heavier materials. I'm not talking about the visual design of armor sets, but the visual appearance of materials.