The advantage of The Scottish Restaurant, such as it is, is consistency. Both in terms of the food, and the standard of hygiene.
It wouldn't be my first choice on a long ride either, but it's available everywhere, at weird hours and probably won't actually kill you. Weirdly, while I don't generally react well to large quantities of chips, I've never had that problem with McDonald's.
Also: Proper loos with hand driers.