It sounds like they are overfitting the recommendations. They really need to get the users explict preference, rather than trying to infer it from what videos

It sounds like they are overfitting the recommendations. They really need to get the users explict preference, rather than trying to infer it from what videos they watch, as that data is tainted by the recommendation engine. Also they have killed the annotation system that most video creators have used to manually recommend videos to their viewers, which is probably going to cause even more overfitting of recommendations.