Kicked out for what? If they want to disincentivize wasting rice, they should charge for leftovers and offer sashimi as an upsell. If they don't, that's on the restaurant.
The restaurant had a to-go by-weight option. For the dine in patrons, you would check boxes on a menu slip with your order, quantity, etc.
Their menu included a simple request that patrons reasonably finish each plate before submitting a new order, that being honest kept their prices reasonable, and that patrons wasting entire orders would be charged on a per-weight basis for the wasted order at their discretion.
Some people are allergic to rice. Some people are on medically prescribed diets. Maybe there's an obscure religion that forbids eating rice. Some people just don't like rice. Are they all jerks too?
That restaurant wouldn't be my preference, but if I did have to be there for an important reason, I certainly wouldn't be bullied into eating something I didn't want to eat. I'm generally strict about wasting food, but in that situation I wouldn't feel even slightly guilty about it.
If they can accommodate your request, and they typically will, you’re golden. If not, you may need to patronize a different business. It is, after all, a reciprocal relationship. If your basic needs aren’t met, and they have a stiff policy on substitution - then yes, you are a jerk for ignoring them.
The actual controversy here is that the folks in the story clearly thought they were cheating the system, and people are responding without questioning that, and some people are questioning that.
Unless you're going to call the entire story fake, then yes we have enough information.
It's up to the market (ie patrons and restraunts) to decide which mix of policies they prefer.
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.