The think in most of the religions that have survived adapted to changing morals. Slavery, human sacrifice, even things like a city having to give food or taxes to a maintained temple (Greece) and such are not longer part of religions that have survived. When you look at Taoism and Confucianism and Buddhism they never had or addressed these less moral practices in the core beliefs so they have survived almost unchanged. Even if the concepts of soul/spirit or deity have changed it hasn't changed how one lives the practice. They also never gave power to a human figurehead who made sure laws were followed and sins were punished. When you look at say Heathenism which is cool to watch on shows like Vikings there isn't large human/animal sacrifices made today in that religion and it's deemed to be ok by the gods who once demanded it. So he may be right in that most ancient religions are gone or shifted to modern principles (non violence) stay active. The only ones to survive as they originally practiced were/ are non violent.
Phenomenal analysis.
