I feel like I'm stating the obvious here, but prices are set by a combination of both demand and supply. The article is focusing mostly on the demand side, but the supply factor makes a huge difference as well. There are significant immigrant populations from Mexico/China/India/Thailand, which means that someone opening a restaurant catering to these cuisines, can hire "ethnic chefs" at an affordable price. In contra…
American and European cooking schools are all modeled on Escoffier's techniques, as passed down through generations of chefs going back to those worked under him directly. It's not just about the cooking. It's the white tablecloths, the wine list, the dress code - it's about a restaurant experience that says as much about who the customer is and what their role in society is as it says about food.
Why require that gentlemen wear a jacket and a tie for dinner? Does it add to the cost of the food? No. It's about standards. If you offer a gentleman a tie so he may eat, you've said something about his station in life. That's why waiters at such fancy places seem like they're insulting you - they're actually insulting you! Because of this, the restaurants are expensive. Of course they're expensive. Not because the food is superior, but because the kind of people who would eat there expect it. At the best, putting prices on the menu is a faux pas. If you have to think about the cost, you don't belong.