They have made so many strategical mistakes it's hard to keep track.
Some changes within the last decade or so that are contributing to declining numbers of JWs:
1. Elimination of book study groups, the most informal, enjoyable and sociable of the JW meetings, contributed to loss of sense of community among JWs.
2. Policy of consolidating Kingdom Halls. I know someone in Europe who has been assigned to three different congregations in the past three years because of consolidation. Now she knows hardly anyone and has stopped attending regularly. Has this happened elsewhere?
3. Abysmal handling of abuse problem both in policy terms and media relations. Many JWs are reading reports in the media and can't help but agree with the criticisms made of official policy.
4. Cart Witnessing is so outrageously unproductive it is clearly demoralising to even the most longstanding JW stalwarts. I know one JW who has stopped preaching altogether after getting fed up with it.
5. The new generation teaching is so embarrassingly stupid that even the most loyal JW is not interested in discussing or defending it on any meaningful level.
6. Crass videos that imply children should give their pocket money, people who leave JWs are useless pieces of bread, gay people need to dispose of the gay at the new system check in. The GB stepped out from behind the curtain and for many the spell is broken.
Please add your own!
Maybe JWs were due to begin declining anyway, but these changes probably helped contribute to decline. I am really interested to see the reports for next couple of years. If they continue publishing the numbers!