Villains in video games enjoy wearing shoulder protectors on a naked torso. Do they really think it’s a good idea? As a matter of fact, it’s a terrible idea, as shoulders are the least affected area of body. This means that your enemies don’t care about your shoulders… at all.
In reality shoulder protectors are sometimes a necessary accessory, but that’s it. They are never used on a naked upper body as the only part of your armor, unless you are a cosplayer.