> Because YouTube doesn't care what you want--YouTube cares what it can monetize.

> You are the product, not the customer.

> Once you internalize that, stuff that Google does makes sense.

They published their algorithm. They rank items according to predicted watch-time. The other poster is probably correct, in that many people use these long classical music videos as background music over and over (i.e. high watch time) and so they're highly ranked.