If the pizza is really good, people might be willing to buy by his rules.
My brother used to ban customers from his oil change business. If he thought a customer was rude to an employee or complained too much about prices, etc. He would tell them to not come back. He used to tell me about customers coming back a few months later and apologizing. I thought he was exaggerating.But then I worked for him as a manager for about a year and saw this first hand. He would ban a customer and they would come back asking to be a customer again. I laughed when a person he banned before I was working there, came in and asked if he could be unbanned. He actually said he was going to be a good customer if he could come back.
My brother charged the most money for an oil change but had excellent service and no blown engines. He used to say "the customer isn't always right" and stuck by his employees.