@jeffjarvis English doesn't have grammar rules, it has sets of common grammar conventions. Not everyone follows the same set of conventions, but it's still English. Example, the split infinitive "rule" was introduced by someone with a hard-on for Latin, but split infinitives have been part of English for longer than it's been Modern English. Same with ending sentences with prepositions.
Judging people based on their use of English is no less bigoted than judging them based on skin color.