I have zero sympathy for Karpeles or anyone else who screws up like this. The reason this sort of thing happens is either because (a) the perpetrators deliberately set out to defraud their customers or (b) they got overconfident and sold a product/service that they simply weren't capable of delivering.
Operating a financial exchange is a serious business. In purporting to do so, you're taking people's money and promising them that you will operate the exchange honestly and competently. From what I've observed and from the private conversations I've had with people who've had first-hand dealings with them, many of the current batch of hot Bitcoin startups are run by people who don't have a fucking clue but have managed to delude themselves that they can build the Next Big Thing in financial technology by faking it 'til they make it. It's like a bunch of kids acting at being grown-ups - maybe one or two might actually blunder their way to success but the vast majority are going to crash and burn due to stupid, idiotic mistakes that could have been avoided had they been willing to listen to advice from people with more knowledge and experience. Of course, the downside of actually doing things properly is that they don't get the growth/traction that attracts investors' attention. The corrollary is that the startups who do achieve the sort of growth curves that attract investors probably aren't doing things properly, whether by cutting corners, failing to balance the books properly, not focusing enough on security or the 101 other things that can lead to an implosion/collapse/insolvency.
While the founders at least have the excuse of being young and foolish, I question the morals of investors who fund teams that clearly lack the appropriate skills/experience to provide proper financial products and services.
It's the same type of one-way bet that contributed to the 2008 financial crisis. If the startup is successful, the founders and investors exit for millions/billions. If it fails, the founders and investors get to walk away unscathed while the customers end up suffering the losses of the founders' incompetence and the investors' failure to properly supervise their investment.
I fully expect a Silicon Valley-based Bitcoin startup to implode at some point and I would not be at all surprised if the resulting clamour from customers who've lost money is loud enough that the authorities step in to begin regulating the space.