You can still make an analog radio yourself without having to purchase a license to do so. At least, in he US (not sure if you need a content license). So that argument is a little off. Plus, in that analogy, the authors argument still holds up - you are buying an app (car radio) that lets you view (hear) content that is otherwise distributd (broadcast) for free.
I think you've misunderstood. Someone said that the issue is due to the app author charging for the app. Someone else said that even a radio isn't free, since you have to pay for that.