One thing I've noticed is that a lot of the things they take issue with cost money, sometimes lots of it. Christmas presents, movies, cable/satellite TV, birthdays, violent sporting events...these often cost a fair amount of cash. On Dec 26th, for instance, many people are pretty much broke after all that shopping. But not Jehovah's Witnesses. That's money that could best be spent in the donation box. The more money you have, the easier it is to give it away. These things also take up time and increase the odds that a Witness might make "worldly" friends who might introduce them to new, cult exposing ideas. It's subtle, cumulative thing that can have a big impact over 5 or 10 years in a person's life. Discouraging them cuts down on the number of anti-WT thoughts and activities a person might have.
Just a thought.
IsaacJ