Not sure that should be the qualifier, there might be more people able to speak Basque in the world than Danish, doesn't stop Danish from being well supported.
Quick google points to about 1M Basque speakers in the EU against 5-6M Danish speakers, there's also the fact that Basque is not the only official language in the country it belongs to, and that it's in fact not spoken in the vast majority of the country.
>One of the EU’s founding principles is multilingualism.
>This policy aims to:
>communicating with its citizens in their own languages
>protecting Europe’s rich linguistic diversity
>promoting language learning in Europe
With this in mind, the first intention fails by an enormous margin, given that 95%+ of Spain doesn't speak an iota of Basque, the second is met handily, given the long history of the language, and I'm not sure what to think about the third, any language whatsoever would serve that purpose.