You don't see the problem because you're using the same number of hours for everyone. When you have some accounts using 500 hours and others using 50 there are problems. And the 500 hour account is more likely on autopilot and reinforcing whatever's already popular.

The unfairness comes when you spend an abnormal amount of time listening. If you listen less than the average user then the bands you like won't be getting x% of your money that lines up with your listening habits.