Narratives can be informed more by the time from which they arise and not by the time to which they want to describe. The authors provide the context here:

Environmental explanations for the collapse of complex societies have been popular topics since William Thomas' 1956 volume on “Man's Role in Changing the Face of the Earth” (Thomas, 1956). This seminal work established the philosophical argument that humans are inherently destructive to the environment (Middleton, 2017; Ponting, 1991; Thomas, 1956), a philosophy that is widely applied in anthropology (Oliver‐Smith & Hoffman, 1999), geology (Nianfeng et al., 1999; Wilkinson, 2005), biology (Ceballos et al., 2015; Meyer & Turner, 1992; Vitousek et al., 1997), environmental ethics (Attfield, 2008), and general public discourse today (Diamond, 2005; Goudie, 2019; Montine et al., 1990; Ponting, 1991; Ward, 2009).

I imagine too the narrative, not despite, but because of the "holes" gives researchers new areas to focus their investigation. Then either buttress the narrative by filling in the holes or to challenge it.

A friend was reading a paperback in the 70's that suggested dinosaurs were warm-blooded. I thought it was an insane premise (because I was maybe 12 years old) but there does seem to have been a tidal shift in how dinosaurs are perceived vs. how I was taught as a child. No doubt it was someone with a theory or narrative that gave pause to some of the researchers in the field, kindled the imagination of some young researchers....

Thus the need to fill holes with assumptions built on assumptions influenced by current societal trends, aka a narrative, & package the product as "Science".