Why would you download the same music over and over and over again?
You act like that is some sort of huge hassle on my part. I mean, I get a data plan that is X big. I don't get a refund if I use less data than X. I don't have any motivation to not download the same song over and over.
And risk when there's a chance that the music you want isn't there tomorrow?
I wish I was that interesting that my musical tastes disappear at the whim of the recording industry. Most of the time when I search for songs on Spotify I get multiple hits for the same song because I get it on the main album, it on some movie soundtrack, and it on the greatest hits album. I am that boring.
I mean I completely agree with the theory, that is why I have a massive mediaserver for video content. Recently when all my friends complained about Netflix losing movies I was very smug that my library didn't lose a single movie. But I REALLY care about movies. A lot. I barely care about music in comparison. I spend more time listening to Audible than Spotify anyway, if the service stops having the songs I want then I will just move to Google Music or the next service.
It is all about priorities and at some level managing every little thing isn't worth it anymore. Heck I have a MASSIVE library of MP3s when I ripped my wife's huge CD collection when we first started dating that just sits on my server never getting used. It is easier for me to point her to Spotify than to upload what she wants to her phone when she wants it.