Nope, and you don't have to. But for those users that are new to the platform (and I have watched quite a few) it makes them feel at home. They instantly know where to look for their apps, they can re-arrange them however they like. It is not for those of us who grew up on Mac OS, then Mac OS X, Linux and Windows, it is for those that have had an iPad or an iPhone and know there is a single location (home) where all your apps are. Launchpad fits that bill nicely.