It seems like such a given. You put cheese on your tacos, burritos, and fajitas. But, traditionally, tacos are topped only with meat, with a few additions like cilantro and onions. As for fajitas, well, if a Mexican saw you put cheese on a fajita (which happen to be Texan rather than Mexican) they may cringe. Fajitas are served with the tortillas separate from the meat, with peppers and onions, sure, but no cheese.
In fact, dairy is rarely used as the main part of your meal. Sour cream is not for tacos in the least. Just like cheese. Speaking of cheese, the word we use for that Mexican cheese dip, queso. Well, it just means cheese in Mexico. Queso = cheese. Not that melted nacho dip we love to pour on Tostitos or even on a nice taco. Which is really not what you think. In Mexico, good luck finding a “hard-shell” taco. They hardly exist. If they do, they aren’t even called tacos. Tacos are served with possibly a lightly toasted or fried shell, but if you had to say if they were “soft” or “hard,” then they are soft. But there are no soft or hard tacos; they are just tacos. Tacos without flour, but corn tortillas. Yes, they make soft corn tortilla shells. And we don’t put them on salads in Mexico either.
Taco salads were invented in California not too long ago. They aren’t even Hispanic. Besides, if they were, you know they wouldn’t have all that cheese on them. And for the grand cheesy finale, not only are burritos not cheesy in Mexico, they don’t exist in traditional Mexican cuisine. Because everything you know about burritos comes from the States and is in no way, Mexican. The cheese, the way we roll them, the way we sometimes fry them and call them chimichangas! All American. So if you want an authentic Mexican dish, ditch the cheese and have a taco with a corn tortilla.