I have personally hit that button accidentally many times while trying to get back to the albums view and waiting for the animations to finish in exactly the way this article describes. I did not want to go to the iTunes store! I just wanted to pick another album on my phone and now I have to double tap the button and navigate back to the music app.
The core issue is it breaks a core UI convention, clicking back and stopping at the beginning, just to push a few more people into a shopping portal. Coming from UX, that's probably the most brazen abuse of Apple's previous good name in design and user experience.
This is a UI concept that has had a lot of usability testing on the Desktop. Personally, I feel tapping through hierarchical menus on a mobile device is just the wrong way to go about organizing/using the system.
I totally agree. I love the edge swiping introduced in iOS 7.