Earlier quoted context omitted.
Spotify would do better to get back to basics on song suggestion instead of trying to guess emotional state - Pandora still finds similar songs by musical elements better than Spotify. A good example to try is to select a song that is out of genre for an artist - an acoustic version of a song that usually doesn't do acoustic for example. The suggestions for similar songs from Spotify all have to do with the artist ge…
My Spotify Most Hated Bug is that I have to be careful what I name playlists now as it’ll completely fuck over the recommend songs if you’ve named it something it thinks it knows about
More widely, many, if not all, of any recommendation algorithm in any field (music and beyond) are not 'intelligent' (meaning smarter than the right human) in any way whatsoever; as noted, usually some tag sorting going on - and where items have been auto-tagged vs manual makes no difference to the quality; you're still dealing with a programmed personality when auto-tagged.
However, they do (appear to) 'work' (exhibit intelligence) when it's performed on a topic of which you know little; there they offer a helping hand.