If somebody comes in a restaurant and speaks no english at all, how the heck are they going to order anyways, assuming no one is there to translate. It's not like restaurants have interpretors on the sideline.
The only reason I will be against this restaurant is due to traveling foreigners. If he were to refuse to serve them just because they don't speak good english, then that is clear nonsense. But for people to live in this country and not know a little english, come on.