I'm very much inclined to think this is just what people get used to. You're used to watching lower framerate, so your brain is yelling "something is different"

I'm very much inclined to think this is just what people get used to. You're used to watching lower framerate, so your brain is yelling "something is different" all the time you're watching. I got used to higher framerates (mostly via interpolation), and now 24fps stuff feels really jerky to me, almost like stop motion.