Can you post examples of what you're talking about? As for reasons why you might be able to see ribs in a lot of art, there are a few: * A lot of artists really enjoy doing anatomy studies, so showing the underlying structure is always fun or informative. * Many -- if not most -- characters that 3D artists make have very…
I think a lot of people over do stuff and don't make these kind of details subtle enough. Its like we can look at anatomical images and know whats there, but in reality more often than not, these sort of details are often covered by water under the skin and fat. If you just hint at the ribs when going for realism its…