It's something that's even more severe if you're traveling in more rural areas, where the non-chain food places are a lot more hit-or-miss (and can have awkward hours like just not being open at 14:00). Chains like McDonald's have a general predictable consistency, which is especially valuable if you've got kids in the prime picky eater phase who are unwilling to try anything they don't know.

OTOH, I'm actually somewhat interested in visiting McDonald's once in foreign countries because their menus aren't consistent across the world but rather somewhat adapted to the local tastes.