excellent study! I only wish you’d had a larger sample size! As I gestate my first sci fi novel, I have often wondered whether first person or third person POV would be more engaging, and considered my favorite authors, as well as best-selling authors in both perspectives.
I recently started Seveneves with excitement, because I’m a huge fan of Neal Stephenson. But 23% of the way in, I got bored. I decided I’d be more interested in reading Thoreau’s Walden, as I don’t recall reading it in school, and basically want to live it now. Instead I bought his collected works, and am VERY engaged in Civil Disobedience. Which has a tinge of sci-fi, at least in the passage where he suggests the US Military would gladly replace their soldiers with wooden men if they could. Now we have conscience-free drones serving in our military.
I think it’s key that fiction make the reader feel as if they’re living it, that’s the highest form of engagement.