My approach at Shopsin's is the exact opposite of "the customer is always right." Until I know the people, until they show me that they are worth cultivating as customers, I'm not even sure I want their patronage.
The brilliance of my restaurant is my ability to control my clientele. The thing that makes my restaurant special is my relationships and interactions with my customers--and the way they relate and interact with one another. With the wrong people here, those interactions don't happen, so to keep the wrong people out when I don't like them. I probably axe at least one party every day--and usually more than that.
I enjoy cooking and giving what I can to my customers, and, in turn, my customers don't just enjoy giving me money, they enjoy receiving what I have given them. Once we've established a rapport, we're absolute equals in my restaurant. But I guess I shouldn't expect newcomers to understand this. In all fairness, they're right and I'm the asshole, because my way is hardly the traditional you-give-me-the-money-I-give-you-a-bagel. I want more from them. I want a relationship.
This could go down as the Book of Five Rings of short-order cookery. Ed Levine is a lucky man today.
'Eat Me: The Food and Philosophy of Kenny Shopsin' [Serious Eats]