They don't, I have no idea how you just find a wallet with 200,000 BTC when others can see it on the blockchain etc. It suggest to me personally that the theories regarding lost keys or badly written key generating software are the most plausible.
I wouldnt be surprised to see a large part of the 850k slowly being 'found' what this does to the price however is anyone's guess
Remember that interview with Karpeles saying the bitcons weren't technically lost, just unavailable? Either gox are lying through their teeth or they had some seriously poor practices. I can't say which is more likely. I've found a few old wallets I'd forgotten about, and no amount of people pointng at the blockchain would have helped me remember where the private keys where. Then again, I have never been entrusted with hundreds of thousands of BTC of other people's money, so my laxness is somewhat more excusable.I wouldnt be surprised to see a large part of the 850k slowly being 'found' what this does to the price however is anyone's guess
That's part of the reason why analogies to individual behavior is inadequate.
Obligations are different when dealing with other people's money, whether as a trusted individual, a corporation or a government.
Analogies to individual behavior do NOT quite fit these other situations.... except maybe in the limited sense that an individual may logically assert that his/her behavior matters to the well-being of his/her family who entrust him/her to make wise decisions with the family assets.