Some people do not have internet connection, so they wouldn't be able to update their system. I know quite a few people who bought their PS3 to use mainly as a Blu Ray player, and with the recent update for 3D movies, they would need someway to download it.
I've worked at Best Buy for over a year, and we have been offering this service since well before I started. We also offer upgrades for XBox 360, Wii, and even Blu Ray players.
Does anyone know if Angry Birds has any sort of trophies? If not, it's really not worth the download, especially since I have it for free on Android