There's a reason. People screwing their phones up and then wanting Samsung to replace them. There's no doubt about it. Samsung adding Knox is pain in the butt for the guys wanting to run TW ROMs or upgrade to the newest baseband. I have a feeling that all manufacturers will end up doing something similar. It's only a matter of time. Samsung went a little far though by adding Knox. They should have just done like Asus and given the owner a choice whether or not to unlock the bootloader instead of intertwining crap within the ROM itself. Yep, that's a little over the top. They could have stopped at the bootloader and been done with it. As with the Asus upgrade, people were not able to revert back to the older bootloader at 1st. In time Devs made it possible. It's not an easy process but it can be done. There's a good possibility that S3 owners may be able to do the same in the future. This update is new. Given time, Devs may be able to work their magic. Remember, the Devs have only been working on this for a couple of weeks. Edit: it took a few months before Asus Devs found a way to revert to the older bootloader.