Well the memory gets hazy, but I wrote about it back in 2011 after a long discussion (not the first) on BioLogos, with many participants of course. I doidn’t want to name names then, and the whole article and comments are no longer there.
But the reason was, essentially, lack of thought.
I was already on board with Genealogical Adam then (it wasn’t named that then), and had, like the original researchers, I guess, twigged that whilst Y-Adam and Mito-Eve said something about the inheritance of individual genetic elements, they said nothing much about human origins.
It was easy to take the message from “We all descend from one man 142K ago” and “We descend from a woman 200K years ago” that those were our most recent male and female common ancestors, and a number of folks who should have known better did. Since there was no contemporaneous couple, as some Creationists misinterpreted the Yadam and Meve story, they reasoned there could not have been a real Adam and Eve.
But I think in the rush to deny that, the genetic mindset attributed more significance to what I called in my article Y-Abdullah and Mitochondrial Yvonne.