If you define buying music through the app itself as 'iTunes' then this is a meaningless discussion aimed at bashing the word 'iTunes'.
You can use the app perfectly well without ever going near the desktop iTunes software, as you say by buying music through the device, or using iTunes Radio.
If you have other music you want to load, the yes, you need to use the desktop app for that.
You can use the app perfectly well without ever going near the desktop iTunes software, as you say by buying music through the device, or using iTunes Radio.
If you have other music you want to load, the yes, you need to use the desktop app for that.
What's your point?