Consider this quote by George A. Smith:
And yet, click here for warnings from The Brethren about actually examining things from an objective position.
If faith will not bear to be investigated; if its preachers and professors are afraid to have it examined, their foundation must be very weak. (Journal of Discourses, 1871, Vol 14, pg. 216)
The point I wish to make is that the truth should welcome debate as much as possible, because after all, it is the truth isn't it? Debate cannot possibly harm the truth because any attacks of the truth will be weak in comparison to the supports. Debate can, therefore, harm only untruth. And yet so few members seem willing or able to enter into discussion about their Church. They want to guard their testimonies above all.
Imagine if the legal system were similar. You're sitting in the juror's box and the judge announces, "In the case of the truthfulness of the LDS church, we're just going to listen to the defense. The prosecution is allowed to sit in the courtroom, just so that we know they're there, but will not be permitted to speak because anything they say might cause us to question the defense."
I, for one, would ask myself why? Is it that the defense's argument is stronger? But if it really is, wouldn't I find out the same thing by listening to the prosecution? Shouldn't I, the juror, get to decide?
Think about this: I just decided that the Earth is shaped like a cube. It's not spherical, and it's not flat. It's shaped like a cube. But I'm unwilling to examine satellite photos, I don't want to hear about the curve of the horizon, I won't even look into geology or astronomy. I refuse to see or hear any evidence that might discredit my belief that the Earth is a cube. I'll talk to you if you're willing to listen to my side, but I will walk away as soon as you show a dissenting opinion.
When someone is unwilling to put his position up against another's, it really makes no difference what his position is, whether correct or ludicrous.