Earlier quoted context omitted.
Your arguments veers close to the "for exposure" payment. People don't go to indie concerts because of a spotify track. Nor to big name concerts. And 20 cents corresponds to around 50 to 100 plays according to the numbers mentioned here.
It is extremely common and often perfectly rational for creatives to do things in exchange for exposure. There is nothing fallacious about this. > People don't go to indie concerts because of a spotify track. Yes they do.
The first requires committing time and effort to get 50 people to see you, 20 of which are your personal friends. The second is making the music you have already produced available to millions of people around the world, with virtually no effort.
Surely Spotify should improve on compensating artists, but all-in-all it is still a better deal for the artist than the "for exposure" gig at the local bar.