It's hard to predict just how long an appointment will take. Some have been done in five minutes, just a brief check-in and new prescription, and scheduling half an hour for that would mean twiddling his thumbs for twenty minutes he could have spent helping someone that arrived rather punctual for their appointment. I think scheduling for the average appointment but allowing overtime for those who need it is the more patient-friendly approach.

Exactly, but if you the patient are late or a no show, then here's a $50 fee for you.