Do you also call Japanese holdouts from WWII asshats?
Old Believers are some of the craziest loons in the realm of religion; not much different from scientologists in terms of connection to reality. His behavior of moving into the woods of Siberia is perfectly consistent with his hundred year old grudge about 900 lbs of potatoes someone failed to donate to his church. This is a story about a profoundly mentally ill man and his equally ill family.
You are correct, when the communist patrol came, a more "rational" person could have claimed to be an atheist... a loyal red and told the communists where some Christians were and thereby increased his odds of living.
The Japanese hideouts are adequately described as asshats
Why am I not the least surprised that you are unable to imagine a reasonable middleground between an insane return to the Neolithic and a complete suck-up to the communists; you know, the way 99% of Russians got by without losing either their souls or their minds? You are free to admire the insane if you choose.