initial-setup-graphical doesn't do anything to try and encourage you to create a user, really. It lets you out without creating one with no kind of warning.

Old firstboot popped up a warning if you skipped the user creation step:

"You did not set up a user account capable of logging into the system. Are you sure you want to continue?"

it may be worth doing something similar; we really don't want to let anyone get through without creating a user unless they're really sure about it, esp. for the graphical install case.