[immibis]

Spotify also doesn't have a right to unmodified client systems.

If their server sends you bits, why should you delete the bits? If you accidentally sent them the wrong bits, do you think they'd be nice enough to delete them? Pre-emptively before receiving any notification from you?

Terms are irrelevant and in most cases have no legal power at all. Fighting back with technical power (as YouTube has done) is fair game though.

The golden rule of capitalism is to do everything in your physical ability to improve your individual situation at the expense of others. Feel free to come to an agreement with Spotify, that neither of you will do capitalism against the other. Until then, you should probably play the game or you will lose by default. Spotify isn't that important but you should definitely get into the mindset of playing the hand you're dealt.