How do Latter-day Saints address the claim that all unique teachings of The Church of Jesus Christ of Latter-day Saints depend solely on Joseph Smith?

Several times in recent weeks the suggestion has been made on the site that all of the teachings and scriptures unique to The Church of Jesus Christ of Latter-day Saints are dependent on one source - Joseph Smith - and that had he not existed (or not made the choices he did), none of these teachings, principles, or scriptures would exist. The claim that these teachings come from a single individual is given as a reason to challenge their authenticity. This suggestion is regularly met with corrective comments - it would be helpful to have a post on the site to reference which addresses the matter specifically. How do Latter-day Saints respond to this claim?