YYA, I am not sure that it is always to their benefit to switch minhagim, they then might become more “frum” than their grandparents but they lose the sense of their identity that existed in their family. A number of movements, active in teaching non-religious or problematic, presume that it is the best for those people to “join the movement”. Perhaps, the activists do not simply have knowledge to guide someone in a different tradition. A better Rav would say – we do X, your tradition does Y.
