I sometimes go to A&W in Toronto Canada, and here I would say its the opposite - A&W is generally pretty reliable and consistent in quality across its locations whereas Mcdonalds can vary quite a bit based on time and location.
Poeple's attachment to certain restaurants is deeper than seeking out the best deal or best taste. Generally I consider an A&W burger superior to Mcdonalds, just as I would consider many boutique burger places superior to mickey ds. Yet the latter has a place in my heart that is really pretty irrational