A friend of mine and I have discussed what I believe is the same issue. We came to the conclusion (strictly based on anecdotal evidence) that more people of our generation, having grown up in front of 75Hz+ progressive-scan computer displays playing Doom off video cards that can crank out 60 fps motion, just aren't happy with 24p source material.
Perhaps our brains are less able to smooth out the difference between 2 frames, or we're processing the images faster than our grandparents could. I really don't know as I'm an audio guy not an expert in psycho-perceptual matters. I do know that even watching movies at the best theaters (DLP, Imax) fast motion on the screen looks to me like a series of still frames rather than a continuous movement. Video-sourced material is slightly preferable at 29.97i, but still occasionally bothers. Also, the bigger the screen's apparent size, the worse the problem bothers me.
I hold out hope that someday true 60p source material on equivalently capable display technologies will satisfy.
"Clever things make people feel stupid, and unexpected things make them feel scared."