Well, look, the point is that it's not just that the black characters are talking funny - they're talking funny in a very specific way that has centuries of racist history behind it. If they were talking babelfish - you're right, that would have been entertaining and interesting. It's too bad that wasn't done instead.
I don't think a creator needs to go back and write it all again if they're not so hasty about writing - or, at least, publishing the first draft - in the first place. It's called research, and listening to other viewpoints.