They have to go "outside", because LDS leadership doesn't provide anything on the "inside":
"...While certain doctrines are enunciated in the standard works and some doctrinal issues have been addressed in formal pronouncements by the First Presidency, there is nothing in Mormonism comparable to the Westminster Confession of Faith or the Augsberg Confession. Few of the truly distinctive doctrines of Mormonism are discussed in official sources. It is mainly by unofficial means -- Sunday School lessons, seminary, institute, and BYU religion classes, sacrament meeting talks and books by Church officials and others who ultimately speak only for themselves -- that the theology is passed from one generation to the next. Indeed it would seem that a significant part of Mormon theology exists primarily in the minds of the members... the absence of a formal creed means that each generation must produce a new set of gospel expositors to restate and reinterpret the doctrines of Mormonism...."
-- Peter Crawley, writing in Dialogue: A Journal of Mormon Thought, Autumn 1982
"Church Headquarters has been receiving an increased amount of correspondence from its members about doctrinal issues. Because of this influx of correspondence, the First Presidency reminded and encouraged LDS church members to utilize their local church authorities bishops, branch presidents, stake presidents, etc before resorting to contacting Church Headquarters. In other words, the Mormon laity was told to quit bothering their church leadership on issues related to doctrine."
-- from the thread Quit pestering us, church leaders tell membership in letter
Thank you for making my point and the point of the article.