This is all news to me.
I left the JW's back in 1966. In the 1970's I was reading from non-JW sources about what was happening in Africa.
In the jungles of Africa there were many different tribal chiefs. If the JW missionaries converted a chief to the JW religion, then that became the religion of the whole tribe. So, for example, if a tribe had 1500 members in that community, they automatically had 1500 new members (i.e. men, women and children, with baptisms for any who were of the age of accountability).
Then afterwards, when the Chief decided he didn't believe the religion anymore, they had to disfellowship not only the chief (for apostasy), but the rest of the tribe as well, since they followed their chief into whatever he believed next..
I am not saying Japanese society operates exactly like Africa, but aren't there a great many Japanese villagers who follow their leaders, and hence they have a lot of cultish groups?
Therefore my question is "If the numbers were/are dropping off, is this part of the influence?"
Rod P.