And I'll throw in my two cents. I've never used Yelp to find a restaurant. Usually I depend on asking locals in person or I read daily/weekly papers to see what places they write about.
I agree that plenty of Mexican food is not hard to make (specially the kinds of Mexican food I've seen people eat here in the US) if you can get the ingredients, but (1) you can't always get them, and (2) there is also lots of stuff that is complicated or at least very labor intensive to make at home, like mole. (Which I make a point of eating when I go back to visit.)
Although I have to say, I don't really get the whole "missing food" thing: if what you used to like eating isn't readily available in a new place just give up on it and figure out what's good where you are. I'd be pretty surprised by a place that has no good food at all.