I think the universe, as quantistic thus probabilistic, is lastly to blame.
I think the human being, as imperfect, is finally to blame.
Are you people out of your mind?
The person responsible for this is the unethical human being(or organization) that decided to abuse that security hole and use it to steal our information. Not the engineers, not Apple.
When you see an old lady walking alone in the dark, do you steal her purse because she did not protect herself well enough? I'm sure you don't... So please, don't over complicate things.
So when you entrust your belongings to a storage company, and they leave the doors unlocked and your stuff gets stolen, do you get mad at the thief? Or do you demand better security from your storage company?