There's an enormous difference between a business taking a loss and making other people's money disappear. If the corner grocer up and decides to close the place, they don't take my property with them. If my dry cleaner had to close up shop, I would not expect them to sell my suit off. Destroying other people's property upon closure is not a normal characteristic of a business failing. That's more than just a business failure.
You're making huge presumptions about a failure that is still in progress. You have no idea if that money actually disappeared or not or whether fraud was involved or not. You're claiming the unknown isn't normal, but you can't know that because you don't know what happened yet, no one does.
If fraud is involved, someone will go to jail and authorities will attempt to recover assets. This is perfectly normal in a functioning market.
You cannot claim that because crime occurs the market isn't functioning.
"what exactly is so worrying? A bad business failed; that's what's supposed to happen."
If all that had happened was a bad business failed, that would not be very worrying. I don't think anybody would be upset if MtGox had simply closed their doors and returned all their customers' funds. What is worrying is how many people outside of the business appear to have lost their property in the incident.
You can judge for yourself whether you feel the market is "functioning" — but if that many people lost that much money, it is absolutely not what is supposed to happen when a business fails.
You seem to be of the opinion that whether a market is riskier than most participants realize (and would be willing to tolerate if they did know) is tangential to how well it is functioning. That's a valid viewpoint. But it still makes sense for participants to worry when they realize how little safety they have in the market.
I didn't say it's what's supposed to happen when a business fails, I said bad businesses are supposed to fail. We can't talk about what happened yet, the incident is still in progress. For all we know the acquisition rumours are true, Gox will reappear under new management and investors will be compensated.
'The money' was mostly imaginary, even beyond the imaginariness of bitcoins. Lots of the coins were bought at a much lower rate; they were ALL valued at the value of the last coin traded. Makes for a big, inflated, imaginary 'loss'.
But in fact only the money invested was lost, which I imagine was an order of magnitude smaller than what was reported.
