Sure, but if the people do know the other language, then why should they be forbidden by law from buying the non-Turkish-UI device if they so choose?
Presumably no-one was forcing Turkish users to buy non-Turkish devices ... ? Or maybe they were, by failing to offer any Turkish-UI devices ... ? Is that it?
Then I suppose the Turkish government reckoned their home market was big enough that the phone providers would comply to a Turkish-UI-only law. And now Nokia is calling your bluff, by ignoring your market.
So, now, instead of having no Turkish-UI devices, you have no devices at all in Turkey.