The "Knights of 'New'" on reddit have to wade through a lot of junk, but everyone else who uses the website benefits from their efforts.
This is a similar deal for Spotify. Some percentage of these songs are good, it might be less than one percent, but if you can get 500 people with decent ears to listen to 1 song each, you can move the needle.
I'd argue this is not as you say, but rather another step towards decentralised marketing.
Because Spotify has its own ranking system and social media/last.fm scrobbling, while a bad song will merely be skipped over, a good undiscovered song with get saved to playlist and exposed via networks to a much greater extent than it had a chance of being before.
Yeah, when that guy was covered recently in the TLDR Podcast, there was no mention that he was basically spamming, and we shouldn't be glorifying people who are making a huge mess while scrounging around for change in the couch cushions of the internet.
This is a similar deal for Spotify. Some percentage of these songs are good, it might be less than one percent, but if you can get 500 people with decent ears to listen to 1 song each, you can move the needle.