Remember: Stupid people learn from their mistakes. Smart people learn from other people's mistakes.
Oh and regardless of whether Mt.Gox is trustworthy or not (I think they are), you should simply NOT put large amounts of money (either in USD or BTC) on a website. This is probably not related to TS's problem but I thought I'd mention it anyway. Put money in, buy bitcoins, transfer bitcoins to your wallet. Now it's safe.
You are right that smart people learn from others mistakes, but stupid people do NOT learn from their own mistakes and keep repeating them. Making a mistake once then actually learning from it is not so bad...
Why do I have to keep repeating that every so often.
I also agree with what you are saying, but now as the bitcoin economy advances not all gox users are 'investors'. While I use gox a whole lot less now (not at all since the Dwolla TOS change), people are even having problems simply depositing BTC, selling right away, then moving to Dwolla then back to their bank account.
There are now plenty of users who sell items for BTC and need to change some of them back to USD for more goods (leaving the profit in BTC like me). And they need a site like gox to be reliable and fast for business to work. For me gox used to be fast, but the last cycle the BTC > GOXUSD > Dwolla > Bank account process took two weeks. While I do not rely on this income to feed my family I can certainly see it being a problem. I do not leave a balance with gox.