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.
Some of you are just making it seem like cryptocurrency is something that everyone will be forced into. Apple is a big company and a tech company with lots of experts working there. We are not even smarter than they are, so they know whats good for them, they can choose to make use of cryptocurrency and also decide its not meant for them. Anywhere, we good with it.