Derrida does not merely attack the idea of an origin. He changes what an origin would have to do to deserve that status.
The familiar version of Of Grammatology can make its achievement sound almost straightforward.
Western thought privileges speech over writing. Speech seems close to thought, intention and presence; writing appears afterward as a secondary representation of something already constituted. Derrida attacks that hierarchy.
But if that were all the book accomplished, TORC would have little reason to classify it beyond M2.
Derrida could simply be offering a different theory of language.
The more consequential operation begins when he asks what allows the supposedly primary term to possess its privileged standing in the first place.
Speech is supposed to provide immediate access to meaning because the speaker is present. Writing is supposedly derivative because it can survive the speaker, travel beyond its original context and be repeated in the speaker's absence.
Yet signs—including spoken ones—can function as signs only because they are repeatable. They must remain identifiable across different occurrences and contexts. Meaning therefore already depends upon difference, spacing, repetition and the possibility of absence.
The supposedly secondary properties of writing have entered the conditions under which the supposedly primary phenomenon can function.
That changes the architecture of the problem.
Across the book, the same operation appears through writing, trace and especially the supplement: what was treated as an addition to an already complete origin turns out to be necessary to the constitution or intelligibility of that origin. The evaluators consistently identified precisely this structure rather than merely Derrida's philosophical conclusions.
The profile is dominated by Abstraction Depth and Inferential Distance.
Derrida maintains the same structural problem across linguistics, philosophy, textual interpretation, speech, writing, presence, origin and supplement without reducing those domains to identical things.
Its comparatively lower Constraint Density and Integrative Compression are informative too. This is not a tiny formal system producing enormous consequences with mathematical economy. The work achieves its result through extended readings and repeated transformations across a large textual field.