There is way more to Mexican food than burritos and tacos. Unfortunately folks who are only exposed to Bay Area Mexican food would never be aware of that.
That's a bit hyperbolic. Plenty of Bay Area Mexican food, 5 mins from my home in fact, has aguachiles, ceviche, tortas, vampiros, pambazo, flautas, sopes, chorriadas, mole, etc.
A bit, perhaps. But it's something famously pointed out by Anthony Bourdain as well. Keep in mind the context in which you're replying: is rice an authentic ingredient in a burrito? Mexican food in the Bay Area is pretty good if you focus on tacos instead of burritos…
And there's two parts to this: first one is that there's not much diversity. Vampiros and flautas are, more or less, tacos. It's almost always the same proteins, same pinto beans, etc. Come to think of it, I can find cochinia pibil in the Mission… at a restaurant that specializes in Oaxacan food. They've got mole (one kind), which is amusing considering that Oaxaca is a state known for it's diverse variety of moles. Anyways, back to arguing about whether SF tacos and burritos are authentic.
The second part is that Mexican food (more than other Central/South American cuisines) is seen as peasant food. You get it from a truck or a taqueria. Occasionally from some place with table service. I can think of two sorta fancy Mexican restaurants (one, if not both, have since closed). Ceviche? Well, I can get that at the Mexican grocery store or the fancy sit down Peruvian cevicheria.
The Bay Area serves up a comically thin slice of Mexican food, even compared to other parts of California or the US.
There are four "fancy" Mexican restaurants just in downtown Mountain View, like 1% of the people and/or land in the Bay Area. It's a big place, with relatively strong Mexican food options. Probably top 5 metro in the world for it outside of Central America.