I read his statement and it seems unobjectionable to me. What he says is that if you water down your religion too far, it ceases to work after a generation or two. That's as true of Jews as it is of Christians.
It becomes more difficult, I agree. I am influenced by my father, an atheist, who was the most moral man I suspect I will ever know. He just was. His values, his honesty, his courage (the ups and downs of his life are almost worth a novel), by example, guide his three sons as we continue on this mortal coil, until we depart. I hold my two brothers in very high esteem, because they have earned it, even though they unlike me, are generally political liberals.