I think Apple's strengths have historically been in hardware and OS design, and not in app design. It's always seemed their stock apps are "anti-bleeding-edge", and this might be intentional in them taking on their philosophy of waiting to be sure they can do feature xyz right before rolling it out. However, I think this is extremely hit or miss with their software. Notes is a solid app, for example, while Mail feels like it hasn't moved forward in forever.

The problem with Apple Music is they are competing with a precedent already set by Spotify. And their team is not only is always working on Spotify's usability but also experimenting with different features (Year in Review, Daily Mixes, group listening sessions, and so on). Apple should have gone in with some killer features or at the very least try to develop a beautiful product that "just works".

I have no idea how app design/development works at Apple, but I get the impression differnet teams work on different products.