I have genuinely, honestly been planning on doing the whole complete deletion thing for about 6 months now, since the election turned up to 11. You know what's stopping me?
I signed into Spotify with my FB page years ago, and now my entire musical personae is tied to my FB account. This [1] is the closest I've come to finding directions on how to do it, and eventually I will, but right now...it's just so damn easy to stay logged in. Agreed that FB at this point in my life is a detriment, but they've locked themselves into other parts of my life that are not. They know this...that was their plan.
[1]https://community.spotify.com/t5/Accounts-and-Subscriptions/...