Only an idiot, or someone who intentionally stuck their head in the sand, couldn't see there was an issue at Gox years before it went belly up.  Why people put money there I have no idea.  Maybe it wasn't obvious what the  problem was (we have more details now) but there was something off and it was only a matter of time.  I got the feeling there were a lot of naive younger people who had money/btc there.