Kong Wen wrote:
OK, so it sounds like this is indeed an American context thing (meaning, it literally is foreign to you). Mayo is pretty much the default fry topping in Europe. Anywhere I've ordered fries there, they'll give you mayo and ask if you want ketchup. Google french fries & mayo or french fries around the world.
I agree that mustard is better than ketchup—yum!—but that's why I didn't get your suggestion... because they go hand-in-hand, not in competition.
Regarding your nude fries assertion, I agree that ketchup is not great on fries, which is one reason mayo wins out. Ketchup is like a saucy soggy disguise for bad fries, whereas good crisp fries are meant to be a delivery vehicle for a nice light, slightly spiced (appropriately complementary) mayo.
Interesting you should say that. Even in my visits to England, Spain, France, and Italy, I never was offered mayo with fries. Now, I think two things could be at play here. a) I wanted to eat local cuisine rather than fried potatoes, so I possibly never even ate fries in a couple of those countries b) they could tell I was American and accommodated me accordingly.
Also, patatas bravas is the preferred fried potato dish in Spain (where I spent 2.5 months), and those are served with a special sauce, so it stands to reason I'd never have encountered it there. Although I did make my share of Burger King runs on busy days. Maybe I'm just unobservant, which is really the thing I was the most incredulous about. I fully believe it's a thing that's done, but I'm just amazed it's not something I've encountered even once.
Edit: Also, as a side note, I don't think there's necessarily anything wrong with doing Splatfests for complementary things. For a Nintendo-themed example, I think a Mario/Luigi splatfest would be amusing. Salt vs Pepper. Etc. Still works, I think!