Recently I watched 'The Wolf of Wall Street' and was quite disturbed by the many naked/nude scenes. They seemed a little unecessary to me, as they could as well have been shot as legs alone or similar instead of showing their entire sex process and their nude bodies. The same goes for the use of abusive language (like "f--k" and other strong adult words). But maybe I just don't see the further use this imagery and language had for the rest of the movie.
So my question is why those particular scenes are included? Is this a technique for marketing their movie or does it contribute to the rest of the movie's story and themes in any way? Is this a necessary part in the movie?