Developers are only able to let their games store data in the /dev_hdd0/game directory via some tool called the game_data_creation_utillity . Sony enforces that with permissions settings on the folders.
So the only way to access something in /dev_hdd0/ with the no_unauth_syscall_payload is to first boot up with some payload, which has the root patch enabled, than fix the permissions and than boot again with no_unauth_syscall_payload.
drizzt, wouldn't it be much more convenient to store everything in /dev_hdd0/game?
As the user can run everything just fine without root access, i see no reason for messing with the file system and unnecessarily alter permissions...
It is very simple. With the no_unauth_syscall_payload you dont have root access to the system. So you end up on something like userlevel on retail/debug console.