If you're a regular reader her at Redmond Pie, or indeed just a modder of all things Android, you'll be more than aware of the benefits of utilizing custom launchers.
One of the advantages that Android has over iOS is that users have more control over their user-experience. If they are dissatisfied with the stock keyboard, launcher, music app etc., they can just head out to Android Market and download something that fits their needs. This may be perceived as Android being an OS that “doesn’t work out of the box”, but it’s more about giving users more choice.