They agreed to the EULA on the services, then, in part, abused their access to those services to hack into other people's iPhones.
I have no idea how we do that. Perhaps decoupling the data-processing services from the data-holding entity might be a possible frontier. One could imagine being able to keep their identity, their core systems & datum wherever they want, & to convert Apple into a mere processor of those personal systems. That way we might not know what Apple is doing, but we at least can watch their black box act against us.
In general, trying to draw further extenuating circumstances, trying to say "except except except" is simply not ok. The phones we carry are part & parcel to their many services, in this weird conflux of computing. It reduces basic core human integrity to be denied access, to be rebuffed by EULA from understanding & witnessing & probing into these core techno-vessels we navigate about with. These mere technicalities presented, that our homes happen to be located inside Apple data-centers, is to me uninteresting & unimportant in the moral, ethical, humanistic & religious discussion and/or reckoning we have fallen into.
If I'm understanding correctly, this wasn't a case of "they agreed to the iCloud EULA because you have to have iCloud to use an iPhone". You don't, in fact. Yes, some services will be unavailable, and...it might occasionally bug you about it? (Not sure about the last, as I do have iCloud) No; they agreed to the iCloud EULA because they were trying to take advantage of unpatched iMessage bugs to break into other people's phones.
I fully agree that the scope of EULAs today is terribly overbroad, but I do not believe that making a legally-binding agreement not to abuse the service to harm other people or steal their data is an inappropriate use of them.