No, that isn’t “Bad English.”
Yonatan Zunger

This is rather disingenuous. And you’ve clearly thought about it enough that you should realise that it’s disingenuous.

You are creating a false dichotomy between understandable (good) and non-understandable (bad) English. It’s not a binary, it’s a spectrum, all the way from standard English, which is the most understandable and thus best to gibberish, which is the least understandable and thus worst. If you are speaking or writing with the intention of communicating with a general English-speaking audience, then dialect is not as good as standard English, because it is less understandable. Even if the reader or listener can understand it with a moment’s thought, it is part of the job of the writer or speaker to make sure that their audience doesn’t need to take that extra moment.

This doesn’t apply in all cases, of course. Perhaps your intended audience mainly uses one particular dialect. Perhaps your intention is not to be clearly understood, but to get some other effect from your use of language. But in general, dialect is not as good as standard English.

You are also a bit out of date on English English. The phrase “The Queen’s English” is not much used these days, because the Queen actually doesn’t speak modern standard English — she has an outdated and upper-class accent. “BBC English” is more likely to be used, although to its credit the BBC is recruiting announcers with a wider range of accents, so that term is also likely to fall into disuse.