If I pay them EUR 10 per month and listen to 200 songs by seven artists/bands, I would like Spotify to first take what they need to run the service (and make a profit) from the money. Then I would like the rest of my payment to be divided among the artists of the songs I listened to.
Because Spotify seems to pool all payments into one large sum, if an artist has some fans who listens 500x each to their songs then those fans will "siphon off" my payment to their favourite artist.