This whole blog post is moronic, if you don't need it, buy a smaller package.
For me the extra price is peanuts, and it's absolutely amazing to be able to play a new game minutes after I bought it instead of hours.
Before we moved we didn't have fiber, and downloading a game could take so long that I would have to wait until the next day to play it after starting to install it.
This also means that I can uninstall games I don't use without worrying if I might want to play it later, this spares me from needing massive storage.
I also prefer to preload media to watch on our media center/TV, and it's nice to be able to have a movie ready in a matter of a couple of minutes.