"Investigative poetics" is attractive because one wants poets to take on, and be granted, the mantle of the histor : to step beyond personal narrative and begin to interpret and give meaning to social reality. Artifacts and documents glow with impersonal mana. Ezra Pound, Susan Howe, many others excavate the archives (or steal from current news bulletins) for sudden brightnesses of recovered actuality.
One of the dangers (Scylla, or Charibdis?) lurking in the detective-collagiste method is that while juggling the dry bones of others' reports, the poet may enervate their own capacity for direct description, original narration, reportage per se. I guess this is one reason why travel poetry and epic multicultural odysseys will never go out of style.
Another complication is that ordinary journalistic neutrality, objective reportage, is about as distant from poetry as any writing can be. Maybe this is one reason a postmodern rhizomatic "poetics of relation" seems appealing. Journalistic objectivity is reinforced by traditions in praxis which try in good faith to leave the work of interpretation strictly in the hands of the reader (after fulfilling the "who what why where when"). A poem on the other hand is from the outset an interpretation. But if the poet, with a comparable vow of idealistic good faith, can follow the path of rhizomatic errancy & self-dissorbtion into otherness, the result will be a new postmodern multivalent "objectivity" (or I should say "non-Subjectivity").
One can say, without getting Derridean about it, that history and texts are symbiotic, intertwined, because so much of human social and historical activity ("agency") is about acting out ideological conceptions, which had their origin in texts and verbal-rhetorical formulations. This is another reason for the appeal of "investigative poetics" : if the poet can just juggle & juxtapose the Poundian "nuggets" in the most exacting way, the reward for the reader will be a historico-literary epiphany : the poet will have succeeded in pre-digesting history itself and offering this golden gruel like a mother hen to the whole brood or tribe. Herein lies the mana of investigative-poetic bricolage.