Dislike of fast food is not social conditioning.
I grew up with home-cooked meals, not healthy but typical comfort food. Once I was old enough to cook for myself, most of my meals came out of the freezer and cardboard boxes. When I was old enough to drive, fast food joints were my primary source of food.
I grew obese, developed a few health problems then met and married a woman who not only knows how to cook, but has recently learned to cook healthier food. I'm losing weight, all health issues are gone and I'm eating the best food I've every had in my life.
Your analogy of a barbarian choosing between a burger and ethnic food is far off the target. Compare apples to apples. Given the choice between a McD/BK/W/whatever burger and a burger made with fresh beef, fresh vegetables and fresh baked bread, the barbarian will steer clear of the fast food one after one bite. (Actually, he'd probably eat both.)
Food does not have to be fancy to be good. It should be fresh, healthy AND taste good. Fast food restaurants provide NONE of those factors.
Try eating fresh food for a month, and you'll wretch at the thought of trying to eat a fast food burger, too. Don't try the "fast food is cheaper" argument either. It's been well documented that buying and preparing food is much cheaper than fast food, not only at the cash register but also at the doctor's office.