Answer: "Hack" was due to weak passwords and no 2-factor, not because of any weakness in Apple's systems.
Systems aren't just technical (software), they involve human beings, feedback loops, interactions, etc. Apple's security systems are in fact weak, just not weaker than the norm.
Actually I think the Apple press release was poorly worded. This in particular:
>None of the cases we have investigated has resulted from any breach in any of Apple’s systems
There was indeed a breach in Apple's system, there just wasn't a system wide breach that compromised all accounts, just a select few.