If the Witnesses have the Truth and have been going to meetings for many years and every week they learn how to be effective in the ministry and learn about the Bible on Sundays and every week have a Family Worship Night, why are they afraid to talk to anyone who doesn't agree with them or question their beliefs? If they have the Truth then nothing can refute it. The truth is the truth. They either can't explain what they believe, they don't know what they believe, they don't care what they believe, or maybe it is as simple as they don't have the Truth. Maybe the easy way out is to say "Oh my God it is an apostate, we can't talk to you". Then they will brag to other Witnesses that they came across an apostate in service like it is a badge of honor.
Even if you were not a Witness and do not go to church and don't believe if God, they would still call you an apostate if you ask them about the overlapping generations or is it fair to need two witnesses in child molesting cases.