An issue I have with my fellow "traditional Christian" believers is their criticism of the BoM. The claims made against this book of very similar to the claims atheists/non-believers make against the Holy Bible itself. When anti-mormons attack the Book of Mormon, those who claim to be Christian somehow forget that non-believers attack in the same manner, the very Bible they hold dear.
I have noticed this myself on a number of occasions. I don't spend much time worrying about it. The way I figure it, our lack of being the light we were called to be is at least one of the causes of their continued rejection of the Book of Mormon without even examining it. I also know that it is my calling to bring souls to Christ, not convert them to any church or book. As Rick Joyner said, we need to know the Lord of the book, even more than the book of the Lord. If we bring them to Christ, who is the living embodiment of the truth, in time the full truth of the matter of Joseph and the BOM will come forth and be known. Until that time, I rejoice that even though they reject the Book of Mormon in ignorance, many of them have and are beginning to accept many of the truths in that book (without knowing it) because of the work of the Holy Spirit among them. One truth...One God.