Waiters are accustomed to dealing with people’s dietary peculiarities when they order. Some guests find joy in manipulating the menu to suit their needs or their budget. It comes with the territory, so servers learn to live with guests who dedicate themselves to finding loopholes to exploit. We understand that a menu is a template for success not a rule book, but of course—like everything in hospitality—some guests take more liberties than others.
There will be guests who request to have their salad served after their entrees because they think it makes them seem more cosmopolitan. It doesn’t. Others will order appetizers as their entrees because they prefer to eat light. It’s not ideal, but it’s forgivable. Occasionally, you have a table that cobbles together small plates into a meal or asks you to course their food in an unorthodox way. It’s pointless to resist. Just give ‘em what they want.
But one menu hack that most servers find intolerable is when a guest orders a side dish as an appetizer. Although there are exceptions, the decision to order a side dish as a first course is often a veiled attempt to game the menu for a cheaper alternative to the appetizer choices. Even the most well-intentioned guests come across completely obnoxious when they do it.

Naysayers will bristle and scorn at the elitism of presuming that menu items should only be served at the times of the meal that they are intended to be. They’ll say if people want a small dish as their appetizer, it’s their prerogative. Why should you ostracize those people, even if the decision is a financial one? These are all valid points. But just because you can do something in a restaurant doesn’t necessarily make it right. You shouldn’t order a sandwich, ask for more bread and then make a second sandwich by redistributing what’s inside the first one. Yet some people do.
Implicit in these choices is a disregard for the experience that a restaurant is trying to craft for its guests. You have no obligation to honor that framework, but if you don’t you may be perceived as someone who abuses privilege.
So follow the template that’s given to you, if you can. It’s better to have the side dish come alongside your main course (as it was intended to be) instead of having it come beforehand even if it means you’ll end up waiting longer or feeling out of place while your tablemates enjoy their appetizers. After all, it wouldn’t be called a side dish if it was meant to be the center of attention. Accepting that will make you a better diner.