It's to some extent self-destructive for YouTube - the I've noticed that when looking for entertainment I wind up being rapidly bored by the recommendations because they're only ever a mirror of exactly what I've seen before - they're not an attempt to challenge or expand on my preferences.

Which of course is what you get from blind correlation driven user feedback - "did you like this?" - if I'm not sure because I'm now exploring outside my comfort zone then that goes back into the algorithm as "no".