But the Watchtower leaders have never tried to give any explanation for why membership is dramatically falling away in the western world. Increasingly worried JWs are instead turning to other sources of information to try and understand why the 'true religion' is contracting.
I know little about the SDAs. Not sure if they believe in some kind of abrupt ending of the world as we know it by divine intervention like the WT. To me that makes a difference in how they explain their numbers. The WT teachings mention that when the time for their great tribulation approaches, their numbers are supposed to dwindle since there will not be any people in the world left to be saved.
To me, that fact that they are doing anything to grow and keep making money instead of accepting what they themselves preach is a major sign that they don't even believe the nonsense they teach. Their response to less numbers is supposed to make them happy that their work is supposed to be coming to an end, but instead they keep reinventing themselves to keep the money coming.