What really raise my suspicions about quality of service that I am considering are these kinds of things:

- who would ever study with an English professor who can't cook?

- work with an architect who can't dance?

- a dentist who doesn't understand miles and point?

I find typos, mispellings and malapropisms to be funny but not necessarily and indicator of the quality of the food ... even the expresso.

Not great analogies ... being able to cook is not a prerequisite for
professing English. Ignorance or lack of attention to detail in the
front of the house, though, may well be an indication of same in
the kitchen.

By the same token, impeccable English is not even the merest indication of being able to cook. Having someone who is not the chef de cuisine botching a detail - be it a reservation, valet parking or spelling - is not necessarily a reflection on the kitchen.

To be fair, as you suggest - "may" is the key word. Often the front of the house and the kitchen are separate realms in significant ways. In some establishments at least. Competence or lack thereof in one is not necessarily indicative of a similar condition in the other. Since it is only "may", I would tend to judge the food on its own merits.

By all means, if illiteracies spoil one's appetite it becomes a part of the dining experience for that person and they would do well to avoid even those places with great food but poor language arts.

With two chefs and a career artist (read "server" ) in the family all working in fine dining establishments in San Francisco, I hear plenty about front of the house and kitchen relationships - the good and the difficult.

I would have interpreted Expresso to be a brand name or trade name or whatever name. As such if a store wants to call itself Expresso, then it is free to call the drinks it serves Expresso too.

Did Frappuccino actually exist as a word before Starbucks used it?

Put it this way. Incompetency in the front of house is not a good sign
for the back of house.

As for food, if the menu is sufficiently illiterate, there is no chance that
the food will have a chance of being judged by me.

My favourite is when they write shiitake (as in the mushrooms) incorrectly by dropping the second i.