[Aelinsaar]

You don't need to crack a safe if you can get the combination from the owner. You don't need to pick a lock if you can pick the key from a pocket. It also goes to the classic XKCD comic about the realities of crypto: https://xkcd.com/538/

As for why so little attention is paid to the human side, I think you said it, "We can't develop defenses the same way we can develop defenses in software." Not only that, but a human being who's brilliant in their role in your company, might be singularly unsuited to learning lessons about social engineering.

I suppose if you want a humorous and somewhat dystopian sci-fi view of how this could be managed... you ever read 'Snow Crash'?