The gap between what is taught in LDS chapels, missionary discussions, etc., about Mormonism's foundational events and what is available at a few mouse clicks distance is dangerous for many Mormons. This problem grows as well-researched evidence that is highly probable to disconfirm Mormon orthodoxy becomes more readily available over the Internet. Many marriages and other important personal relationships have foundered as this information comes thundering without warning into the lives of people who are unprepared to deal with it.
In my view, Grant Palmer is doing a profound service for the LDS community. He is saying things that many LDS leaders know need to be said, but cannot say. He is an agent for precisely the kind of mainstreaming change toward which LDS Church President Gordon B. Hinckley points when he de-emphasizes things like "man can become like God" and emphasizes Christ's role within Mormonism.
If there had been more open-about-the-past and continuing faithful people like Grant Palmer within the Mormon community as my generation came to maturity, many of us who have left Mormonism behind would likely not have done so.