Naturally, under German occupation they could do little else since you don't build a national government under an occupation. The past 20 years is their first chance, that they are not occupied by either Germany or USSR.
Post-apocalyptic sleep
Not exactly true. Back then Ukraine's militant nationalists were primarily concerned with cleansing their region of all non-Ukrainian minorities, be they German, Russian, Polish, or Jewish. They collaborated with the Nazis against the Soviets, and among other atrocities were responsible for the mass murder of thousands of Poles.
Naturally, under German occupation they could do little else since you don't build a national government under an occupation. The past 20 years is their first chance, that they are not occupied by either Germany or USSR.