Not every bodybuilder that looks like him there are levels of bodybuilding depending on what you want and your area of sports some that are not in any competition may not really train to look like him but those that contest for this Mr. Olympia always look at such because I have seen several pictures of them there are bodybuilder that train to be fit and also have a good body shape and a better posture so what they put on can easily give a nice look.
For me I don't really like the way this people that contest for this "Mr. Olympia looks, I think the name you gave to them is right they looks like a monster.