I hear what you are saying Marlespo and I agree it is best to have an appointment but it is curious as there are clearly displayed in boxes at the Embassy for processing the passport paperwork and the two boxes at each station read: 'With Appointments' and 'Without Appointments' respectively.
So there must be some established procedure for processing passport applications/renewals sans appointment. We were asked along the way if we had an appointment and we answered, 'no' and were handled with kindness and extreme promptness, despite the full room of waiting folks. There was no place to sit there were so many people waiting for their passport appointment. From the time we arrived to the end of the process, it was 1.5 hours.
I must say, too, I have had nothing but the best interactions with all the Embassy employees, every time we go there. Every time we need the notarial service, or a passport issue or some other thing, every employee has been so friendly and kind to us.