I empathize, but in Apple's view, all of their users have access to reliable high-speed internet, and are within proximity to an Apple B&M store. Everyone else who doesn't fit that profile is an edge case, and less, if any, concern. Unfortunately, despite the investment, Apple's online services have been adequate, but no more. Just last week, I was getting 404 errors trying to update an app. I had to alert the author, who alerted Apple, before it was fixed.
In my sampling of iPhone users , they function solely as standalone devices. None ever make a connection to iTunes, or sync to a computer. Everything is handled through iCloud. The iTMS handles it all -- your apps, your music, your videos, your backups. Owning your own stuff, like CDs, and DVDs, is passé.
The media companies love it too, because 1) they've gotten to a point where people will pay for entertainment again. 2) payment per listen/watch has always been their holy grail. Subscriptions are a big step toward that goal. No ownership, just rental, and a continual revenue stream.
Back on topic:
I've tried more things, like de-authorizing the computer, signing out of the store; it's just broken, and from my research, not an anomaly.