That thread only answers the question in a shock factor way and doesn't really explain practical basics behind BTC's recent drop. If there was a practical answer it was buried in a lot of emotional diatribe. Here's the answer as plainly as I can put it:
Mt Gox froze the trade of BTC only allowing people to sell their BTC for cash resulting in more supply of bitcoin to the open market by forcing a mass liquidation of bitcoin to fiat currency. The failure of Mt Gox encouraged FUD and many of those using Mt Gox are less likely to return to bitcoin OR it will take a little bit of time for them to transfer funds back into bitcoin on some other exchange.
Mt Gox's irresponsible actions would be detrimental only if other large exchanges failed. But, it does prove how devastating it can be when a bank/exchange fails. It's history repeating itself on a smaller scale. It has been a deep cut in the collective community soul and will be interesting to see how the bitcoin community reacts.
Okay, I've gone off into my own version of emotional diatribe so I'll just finish with:
I think it could be argued that Mt Gox was criminally negligent in this case.
