Do they give permits to people who only speak Mexican? Idiotic.
That’s not why the requirement for Spanish on the sign is in the law. The real reason it is there is to make the sign as large, ugly and onerous for someone to post. A fully legal 30.06 or 30.07 is quite large and obvious. Most businesses do not want to have such things visible, so they will shrink the sign or omit the Spanish part.
But if you shrink the sign past the legally definied minimum size or leave the Spanish off, it is no longer valid - it can legally be ignored as if it were not there.