It's interesting that high-end restaurants offer the promise of personalized service, without really needing to deliver. This is a key way in which they are able to provide a premium experience while still scaling it to handle hundreds of patrons every night.
You'd think that fine dining establishments would have a huge array of amazing food to choose from. In fact, menus are much shoter at fancy joints (sometimes no menu at all, just prix-fixe at the whim of the chef). You generally don't get to choose your table in a fancy restaurant. And you have to struggle to get reservations, when it seems like for a premium-price you should be able to eat in a place that isn't so crowded.
It's a lot less likely that people in high end restaurants will ask for substitutions or be demanding, because they already presume the experience will be good. And they presume that the chef and staff know what they want more than they themselves do. Of course, the restaurant will give personalized service when you ask (at least the not-ultra-snooty ones), but like a retailer who counts on the fact that not everyone will send back the mail-in rebate, the restaurants runs smoothly because so few patrons need anything that isn't well planned in advance.