[eru]

Why? Charging for leftovers and offering sashimi as an upsell is certainly one mechanism the restaurant can use. And so is reserving the right to refuse serving customers they don't like, and making use of that right every once in a while.

It's up to the market (ie patrons and restraunts) to decide which mix of policies they prefer.

[_jcyi]

They're free to use that mechanism, but it shouldn't come as a surprise to the customer. That accomplishes nothing other than wasted food, upset patrons, and credit card disputes.

[eru]

You are right in some sense.

Though it wouldn't come as too much of a surprise to reasonable customers when you kick out unreasonable customers.

You are right that (bad) surprises are bad for commercial transactions. Most restaurants, especially all-you-can-eat joints, have some rules written down somewhere about these kind of situations.