I understand the Wir sind ein folk argument, especially for Germany which has always been a homogeneous nation. On a sentimental level, I also understand it for Nigeria, for the “national aspiration” we’ve always paid lip service to.
But it is a sentimental aspiration. We’re not Germany. We have a multiplicity of language and culture each of which is as valid as the next. When we celebrate the Nok, the Ifẹ̀, the Benin, and Ọ̀yọ́ arts and civilisations, we never say “Don’t say Nok/Ifẹ̀/Benin, just say ‘Nigerian’!” That will be foolish. We celebrate that diversity for what it is: individual contributions to the national pride. It is the same with language. I certainly hope that you’re not advocating that every world language be given up so that we can all speak English!
In any case, the advocacy for mother tongue use is not as a means of separation but a means of celebrating each single thread of the national tapestry. There are many advantages for this, one of which, ironically, is actually the enriching of English itself. The role of local languages have reduced since colonialism and will probably continue to do so, as I said in the piece, though I wish this weren’t the case. India certainly was in our shoes at some point, yet their multiplicity of language has never become a disadvantage to national development. Yes we have over languages and dialects. I’d rather English becomes one of them rather than the only one.
I am very happy to have the argument about the role of multilingualism in Britain because it shows the exact opposite of what you cited. Wales, which is as British as they come, which is also more patriotically committed to a United Kingdom than Scotland, has always celebrated its Welsh ancestry, language and culture. You’ll note that there are no movies or movements about Welsh political rebellion. That is because a celebration of heritage and culture is not always the same as a desire for separation. Ask the Scots why they want to leave. It has less to do with language and more to do with other historical grouses. The reason why the Igbo seceded in 1967 wasn’t because the British had forgotten to make them learn English. The Hausa, after all, were more attached to their language than every other ethnic group. You get the point.
Nor should we aspire to be like Germany. There is a reason why the United States doesn’t have an official language in its constitution. Yes, English is used, but that’s because it’s convenient. Not because it is mandated. It’s because the country was founded against the idea of a colonised people bound to the language of the oppressors, but as a multicultural, multiracial, multi-people republic/democracy with a common ideal, yes, but differing ethnic identity. The name Los Angeles is Spanish, while Illinois is from a native-American word. Minneapolis combines a Dakota word with a Greek one. Everywhere in the country you see an acknowledgment of the benefit of multiculturalism. But also in public policy, children in many states are allowed to learn in their local languages. None of these have made America less a country signifying a pursuit of a certain recognisable ideal, and national image.
More importantly for me — as a linguist interested in the survival of languages, and as an educator convinced of the arguments of better outcomes from indigenous language teaching — it’s more than a sentimental pursuit of a cultural identity as much as a commonsense recommendation for better educational outcomes. Madness, after all, is defined as doing the same thing over and over and expecting a different result.