I don't quite understand why minorities have to have everything in their native language if they chose to live in a foreign country.

I guess it comes down to how the minority group ended up where it is, and how one would define a "foreign country". If a group of people migrate voluntarily, the receiving country would have a legitimate expectation that they'd learn the language, and adopt at least some aspects of the dominant culture.

If a group is conquered (or enslaved), or through some accident of history ends up a minority, I personally don't believe they should be coerced into adopting the ways of the majority. It would be compounding an injustice.

I'm not sure where the Kurds fit in to this - did they really "choose" to live in modern Turkey, the way that Turks who migrated to Germany did?