When they really need to. But they'll fight it hard! Apple's business model is to lock everything down -- very closed indeed. This does not align with the goals of bitcoin, at least, how I perceive them.
tl;dr Apple = closed. BTC = open.
I think that Apple does not consider Bitcoin as a competitor. Bitcoin is most likely treated as a payment instrument. High volatility in the market makes it difficult to accept bitcoin. If the cryptocurrency market becomes more civilized, then I am sure that Apple will accept payments in Bitcoin as well.
For now it won't get good information from Bitcoin for all other types of products because the falling price of Bitcoin makes everyone start lazy to do something new.