Rav Hutner writes that he once told the a kibbutz gathering in the 1950s “Your grandchildren will either have (somewhat) returned to Torah or not be living in Israel. ” That does seem to be what happened to a large degree.
Now take all the other anti-frum groups of the 1950s. Name a single one who that could have been said to as a correct prediction about where their ideology will lead to . If their grandchildren today are Jewish at all they are probably even more anti-frum. And anti-Zionists to boot.