Is this that bad? I'm not saying your way is bad -- but both seem reasonable. Are some artists heavily benefited or harmed because their listeners listen to much less or much more total music than the average?
I'd guess that Spotify's model benefits artists that make radio-friendly or ambient music because some people will listen to them 8h a day while at work. Nobody listens to the same amount of intricate and challenging music, which is probably more expensive to produce in the first place.
I believe it's bad. It's making all of music more generic.
There's composers and producers with quite high production values, very complex and intricate music, the kind you want to pay attention to, in order to get the most out of it.
But I don't listen to that music all day. I got other music for background.
In my view the latter is not more valuable because I listen to it for more minutes.
When it was CDs I'd pay roughly the same for my Autechre as my Kruder & Dorfmeister.