The soviets were soft on nazis. If the soviets had done just a fraction of what nazis did they should have wiped out the germans for example.
Nazis seem to have deep roots even today it seems, thus the denazification do today seems important. Too bad that the nazis implicate innocent people like normal conscripts in ukraine but that's another reason for denazification eventually.
Many nazi criminals got away from proper punishment in the Nuremberg trials, not the opposite.