Spotify is saying "You may download this, but this program under someone else's control will forcefully delete this data from your machine"
My machine is my own. If I wish to grant other users access to the machine or data on it, cool. That's my choice. If I buy a program to do a task, good. When your program starts taking orders from "nameless faceless someone else", we have problems.
Locked in APIs are just as much as a scourge. When you use them, you're locking yourself into an ecosystem that will go away. It's not a matter of if, but when. I'm less hesitant when these APIs used are standards compliant (where I can go 'down the street' and plug in their credential info)... But that's not where money is.
Lockin is where the money is. And I'll fight it tooth and nail. I already am doing the fight against bad IoT.