Conspiracy theory as allegory

In an article expressing sympathy for 9/11 skeptics, Michael Truscello critiques conspiracy theory as allegory:

"[For cultural critic Jeffrey Melnick] this “grassroots rebellion” is not to be taken seriously on its own terms, but rather as a “revolt not only against governmental control over 9/11 inquiry but also as a critique of the centralized control of American media held by corporate actors such as Clear Channel” (p. 43).

Truscello critiques what he views as the wide brush with which Bratich, Fenster, Dean, Birchall paint conspiracy theory, particularly 9/11 conspiracy theory:

by assuming the label “conspiracy theory” applies to all 9/11 skepticism, they condemn even demonstrable falsehoods to what Orr and Husting call the “freak show” of postmodern American culture; and by focusing on how the theories are able to circulate, rather than whether the theories possess any epistemological legitimacy, they avoid questions regarding the very definition of conspiracy theory (33).

Truscello, then, would seem to pose an "epistemological test" for would-be conspiracy theories: if such theories have more truth value, then they should not be labeled conspiracy theory. This is an old argument, and a bit defensive, but, as Truscello notes, one that continues to be worth making as long as legitimate skepticism continues to be dismissed via the label conspiracy theory

In contrast to this group of "academic treatises" Truscello poses the more heterogeneous references to 9/11 embedded in film and television: V for Vendetta, Rescue Me, Jericho, Heroes, and others, arguing that such a field renders visible 9/11 skepticism that these academic treatises obscure:

The difference between these examples of popular culture appropriation and the academic treatises on 9/11 in American culture is that these films and TV shows at least contained consideration of the ideas in circulation online, whereas mainstream academics seemed to believe 9/11 skepticism was either marginal enough to ignore or unconvincing in the forms it has appeared (57).

The question here: why is 9/11 skepticism worth discerning? Also, does the fact that an idea resonates through popular culture translate into "useful" or "worth promoting"? After all, popular culture is a vast and uneven field, capable of harboring both the most hopeful subversions of power and the worst petty racisms...