It would have been the normal thing to do. But the USSR went the other way because it was committed to the idea of being several separate soviet republics, so i

It would have been the normal thing to do. But the USSR went the other way because it was committed to the idea of being several separate soviet republics, so it pushed the idea of Ukrainian language and culture as something distinct from Russian in order to present the idea of a Soviet Ukrainian Republic as something distinct from the Soviet Russian Republic.