Truth should be able to withstand scrutiny.
If I had a nickel for every time a non jw asked me why jw's will not read their material (Christian tracks, books, etc...) in exchange for jw literature.........$$$$$ I'd be rich! but then I have to explain the whole thing to them, getting in time, placing litter-ature, and never, ever learning about other opinions from anybody but the gb or else jehoover will be mad at them and they may get zapped out of existence at the big A.