These days, most US consular sections use appointment systems of one kind or another not only for IVs and NIVs but also for various ACS applicants: notarials, CROBAs, and the like.
Well, good. Except...
Does this mean that when an applicant arrives at your mission ten minutes before the appointed time, s/he is admitted immediately? Is s/he called to or welcomed at the intake window at the exact appointment time?
If so, good on you. If not, you do not have an appointment system; you only have crowd control.
Madam has heard far more often than she likes the argument that either
1. This is the best the consular section can do, and/or
2. The people here don't expect any better.
To which, after a suitable expletive, she must respond, "No, it's not" and "So what?"
If you made an appointment for any purpose anywhere in the US and that appointment worked the way that your section's does, would you feel you had cause to complain?
If so, fix it. Remember the part about setting a good example, and the relentless need to present the best possible face of the US in all interactions overseas? Please. You have an appointment system; now make it work like one.