I don't think it's as heavy-handed as you suggest. Most of the app's navigation is handled by tableviews and collection views. The dial that you reference is really a sideways scrollview (albeit with a material skin)--this controls a non-skeuomorphic list in an intuitive way that isn't confined to the limitations of a physical radio's interface.

I'll grant that the tape deck is outdated, but it's a largely hidden little visual treat that suggests a hidden mechanism underneath AND provides visual feedback on playback speed.

Skeuomorphism is bad when it restricts the UI to the properties of physical objects, but in this case Apple hasn't done that.