How much should you trust an opinion on your creative, fiction writing from someone who generally hates reading and almost never reads anything but nonfiction autobiographies?
I would nod, smile, and ignore the specific criticism unless it’s something that dovetails with something I or other people have noticed. And then thank the person and back out of the conversation.
I mean, it’s possible that your person has noticed a glaring flaw in your work! But it is also possible that they are being cranky because the piece is not following the narrative rules for nonfiction autobiographies, or that it’s not what they ‘expect’ in reading material because it’s not a nonfiction autobiography. I’d value the opinions of someone who likes reading creative fiction much more in this circumstance, and that includes your opinion.