To me, the Dark Ages are "dark" because of the knowledge that was lost, if not intentionally destroyed. In this sense, I do not view the coming new Dark Age as a return to subsistence farming or involving the complete loss of modern technology, but as the fulfillment of Neoliberalism's mission to engineer a "great forgetting" of classical liberalism and other fruits of the Age of Reason. The ideas of people like John Locke and Thomas Jefferson had a power beyond that which even those two intellectual giants could contain, and they must be destroyed in their raw form and viewed onlythrough the Neoliberal prism. (Note: my thesis is that both Locke and Jefferson crafted their ideas with the aim of controlling the masses, not empowering them.)
The sociopathic dogma of Neoliberalism drives narcissistic institutional values that prevent the masses from thinking beyond themselves, encouraging them instead to embrace selfishness, or "self interest, wrongly understood." The purpose of the coming Dark Age is to forget the classical liberal ideas that resulted in self interest, rightly understood, i.e., self interest that recognizes the good of the community as part of self interest. Mix in the "now-opia" (or is that "now-opiate") of the modern consumer culture, and you have a perfect set of conditions for a new closing of the Western mind.