Your point is a valid one, but I want to add to it that it is also a matter of expectations and how one listens.
Years ago, when I was dating someone who spoke Russian as one of her native languages, we had to do a funny compromise when watching films together with her parents: they didn't speak a word of English, so we'd use the Russian dub with English subtitles.
I noticed that the Russian dub was just one man reading a translation in a flat voice over what was happening on the screen, no attempts at voice acting or matching the emotions. Usually the dub would have a split second delay to the actual lines, so you'd still hear the original voices for a moment (and also a little bit in the background).
At first I found it very jarring, but they explained that this flatness was a feature. You'll quickly learn to "filter out" the voice while still hearing the translation, and the faint presence of the original voices was enough to bring the emotional flavor back. The lack of voice acting helped with the filtering.
This turned out to apply to me as well, even though I don't speak Russian! My brain subconsciously would filter out the dub, and extract most of the original performance through the subtitles and faint presence of the original voices. Obviously the original version would have been a better experience for me, but it was still very enjoyable.
Of course a generated audiobook is not a dub, as there is no "original voice" to extract an emotional performance from. But some listeners might still be able do something similar. The lack of understanding in the generated voice and its predictable monotony might allow them to filter out everything but the literal text, and then fill it in with their own emotional interpretations. Still not as great as having proper story teller who does understand the text and knows how to deliver dramatic lines, but perhaps not as bad as expected either.