Many good comments so far, but NightHawk to me has the most pointed spiritually realistic points down. I will add, when it comes down to it, if you don't have the Spirit, you are only reading words and will not recognize what is said, just like many of the Jews did not recognize Christ for who and what he was, when he made his advent on the earth.
Most Christan's recognized the Bible Scripture, that says, the Church will be restored, so what is so mysterious, that that actually happened. But then I guess, one can say, many have tried, and many have failed, but you cannot disclaim all of them.
NightHawk says too, a change needed to happen, with the new truths revealed. The Book of Mormon, may not be so clear on this matter, of needing a restored Church, but the Doctrine and Covenants is. You see in Scripture, when ever a people are willing or ready to receive the Gospel, our loving Heavenly Father always provides a Church with his truths.
I also belong to a Jewish Nazarene site, of Christan Jews, some very interesting perspectives. The hang up is not in our similar views, but in that most believe the Book of Mormon cannot be the word of God, because it is not the Torah or etc, and has too many problems, to be compatible with what they know. They seem to be in the same boat as many non LDS, they are fixated on the Words and not using the Spirit, which is the testifier of all things.
That person, BOMC thinks that everything should solely be based on the Book of Mormon and even if it were why would he think Joseph wasn't supposed to start a church when he specifically was told that through him the truth will be restored?
I feel Joseph was heavily influenced by the preachers of the time and saw having a church of his own being a great help to his family who were in debt at the time.