Re: No thanks
The point is that you can't change their assignment easily. You can if they are downloaded to your PC. If you, like I do, have too much for the memory of your phone, or you simply don't want to clog up the memory with stuff, you stream your purchases from the iTunes store. There's no way to mark a file as "do not play in random shuffle", e.g. as someone pointed out various movements in classical music which simply don't stand alone as a track. You have to hide the purchase, which means you can't then use it without faffing around unhiding it from a web browser.
Apple's Music... the only music app without an actual "play" button. Go on, try and find it. There isn't one unless you've got an already playing track and you've paused it.