Once again people on HN hate on cryptocurrencies for no good reason.
This isn't a cryptocurrency problem, it's a fractional reserve banking problem. These centralized exchanges are unregulated banks in disguise. It's no surprise to anyone that they exhibit all of the problems of unregulated banks. Problems such as "we used customer deposits to gamble, lost everything and are now insolvent".
To think one of the reasons cryptocurrency was invented was to end the need for such things...