Right-click actions are, by their nature, hidden, and there's often no indication that you can right-click to get more actions. Case in point, the windows taskbar's system tray. Lots of icons, most do something when you click on them, but often they do different things depending on how you click. Since clicking does something, it's not always obvious that what you want might only be available by right clicking.
Also, depending on which mouse button you use, 'safely remove devices' will either give you a menu of devices to safely remove, or give you a menu with one option, which opens a window with a list of devices to safely remove.
Critics have derided the Mac's no-right-click mouse for ages, but for the non-technical user, not well-versed in the behaviour of a computer, it makes much more sense.