Pretty sure that's what they were trying to do. I know for sure that on iPhones, if you ever sign in (which I think is required), wiping the phone doesn't matter, it's still locked to that account somehow -- a ROM chip on the board stores the account info somehow I think? I think their computers work the same way now.
On other systems, logging in means that: you've logged in. And you should be right: wiping the OS should always remove any login/account status. If Apple wants to provide some system like this for people worried about theft, cool, let them opt into it. But don't force every user to.