'Fluent speakers of Maori and English'

Who is judging fluency in Maori, and what criteria are being used. Why is it necessary for applicants to be fluent in English, when Maori was spoken in New Zealand long before English was ever heard, and is still spoken as a living language by many thousands of people? Many generations of New Zealanders have learnt the Maori language without reference to English where Maori has been taught orally and not as an academic second language to English. Obviously a pakeha criterion.