Taking reservations may have created the false impression that one could show up later in the day without the need to wait in a long line. I concur with you in

Taking reservations may have created the false impression that one could show up later in the day without the need to wait in a long line. I concur with you in everything you said, but I think it is important to remember that that impression was false only because Apple arranged it that way deliberately. As others have stated, they knew the maximum number they could serve in a day and could have refused to reserve more than that, or made reservations for specific times of day and then ensured they had enough staff to cover those reservations. If they truly got overwhelmed by surprise (say some employees got sick), they could have started handing out numbers so people could be free to walk away for a bit and return closer to time based on their number. Etc.