Good point Jambon1
Thinking back on the years I was a JW. I have often thought the same.
Once a year you would see the non-believing Husband or Wife of a JW turn up or some other relative. I remember one JW sister who would bring her husband and 5 children, who would never be seen again until next memorial.
Some of these sisters who dragged their husbands along seem to think that it would help their husbands get through Armageddon, because they had after all attended the Memorial over the years.
You would see those who had not been to a meeting for months, probably since last Memorial.
Those with "bible studies" with bring them along, yet even having been studying with such ones for months, the Memorial would be their first time at the KH. Then you still wouldn't see them again afterwards.
The WT should ask itself if the attendance jumps by 7-8 million on that day......why aren'tall those people JW's then.
Interestingly when you look up JW members in an encylopedia or similar they always seem to give the number of JW's as 12-14 million. Do the publishers ask the WT for their numbers, and get given the memorial figure, rather than the actually number of baptised JW's.