Thank you for the folder write deny -solution, much appreciated! I am baffled how this has been overlooked by Spotify devs for so long. Preventing the useless data dump doesn't affect the usage of the app in any way, so what's the point of the dumping in the first place. It's just there to **bleep** off customers and fill their disk space with useless clutter.
Has anyone found a solution for Android (or any mobile platform)? I would love to prevent the writing there as well.
I believe Spotify works as a p2p network and the cached data files here are actually 'pieces of music' which can then be transfered to other users, like a p2p network, when they listen to this particular song(s). This releases pressure on the Spotify servers, since they don't need to transfer every song to every user who listens to it. You may delete all the folders inside the 'data' folder and it will be recreated (with new files) as you listen.