[true_religion]

Their policies don't necessarily need to be due to 'ethics' or laws, but just their opinion of what makes a good marketplace.

Perhaps they feel that repackaging other peoples content leads to needless confusion about what is official and not, since anyone and their cat can put up an app that wraps a Youtube channel.

Maybe they feel that apps like that are low quality, so to set a bar they'll restrict it to only the actual rights holders who have a more vested stake in making a good app.

It's really a business decision.