It just seems like there's a paucity of signal from which Netflix could come up with anything intelligent. Movies are many hours long, and there are many reasons I could be watching something. What does it mean that I allowed a movie to play to completion? Was I even paying attention? Did I decide I hated it 3/4s of the way through, but finished it just because I cared about the plot?

TikTok, on the other hand, has way more data. Things like time-to-swipe, shares, comments presumably form the basis of some sentiment metric.