User lock-in is all that Apple really cares about - the entire app approving dance just adds a nice toolset to find arbitrary reasons for blocking apps that might be interfering with Apple interests (https://www.recode.net/2016/6/30/12067578/spotify-apple-app-...).
This is scammy and awful developer behavior, but probably best to keep in mind there was no overtly malicious content actually in the app regarding security, instead preying on user ignorance.
FYI: You're not wrong on this, I have found multiple apps which try to grab sensitive info and phone home with it, only pointing out your link may not be the best example to use.
User lock-in is all that Apple really cares about - the entire app approving dance just adds a nice toolset to find arbitrary reasons for blocking apps that might be interfering with Apple interests (https://www.recode.net/2016/6/30/12067578/spotify-apple-app-...).