Earlier quoted context omitted.
That's actually not true. It can do nothing about M of N cryptography. (That's when a key is broken up such that there are N parts, and at least M (less than N) are required to decrypt. It doesn't matter how many rubber hoses you have, one person can fully divulge or give access to their key and it's still safe.
Sure, so you hit all of the people that have all of the pieces. Problem solved.
It's not like these keys are shared among disinterested strangers who have no attachment to each other.