My thought experiment of a chain wouldn't directly compete with people choose McDonald's every single time. It'd be for people who've seen the light, and know you can't eat McDonald's, sustainably, indefinitely. That population isn't everyone, but there's a sizable number of consumers who are diet conscious. That's the target market. While McDonald's food is designed to have a certain effect on your palette, you haven't appreciated a skilled cook's entrees if you think there's no realistic competition. Deep, rich, meaningful flavor could absolutely compete against the engineered taste of McDonalds.