This "its not so bad to learn standard English" argument reminds me of the argument around French and English in parts of Canada. Yes, English is the most common language. No, its not so bad to learn. But is it really so bad for others to learn French? Or for neighbours/community members to sometimes speak in French rather than English? I think the root of the disagreement with French and English is that when we say 'everyone speaks English so you should speak English' we are in some sense creating a hierarchy of languages - rather than saying - I can speak some French, you can speak some English, maybe we should both try to share both our languages - which implies a level of equity in our experiences.