Wow, that stat is so real. My friend's book club tried to read a dense history book last fall, and it was a total mess. Half the group didn't even finish the first chapter, and their meeting was just people staring at each other in silence. They switched to a mystery novel the next month and suddenly everyone had three pages of notes to talk about. It really showed me how hard it is to get a whole group excited for non-fiction.
Oh totally, that stat tracks with my experience. My old book club tried a memoir once and it just killed the vibe for a month. We went right back to a thriller and the chat was instantly way more active.