Who is Karlaplan? And why choose Google Docs to share information which Google may dislike and remove?
If Google pulled the doc they'd likely get a lesson in the Streisand effect, and they likely know not to try. Posting it on Google docs is actually smart bait by the author in my opinion-- intentional or otherwise.
Regarding the thesis, it seems to me that unless you have read the advertiser guidelines then you are always going to have your viewing manipulated in ways you do not understand. The recommendations are really 'how best to monetize you'. So with music you may end up with mainstream artist recommends, not because the songs are inherently popular, it is just that they can be monetized.
Therefore, the best way to explore the back catalogue of an artist is to upload your own video and to then see what tracks by your favourite musicians you can set to it. So even within normal YouTube there is a 'better' search engine, better for you but maybe not so monetizable even though that is what the widget is about.