Investors like security and the bitcoin is pretty much the opposite of secure. They also like secure exchanges and the bitcoin exchanges are pretty shady compared to mainstream exchanges. That is kind of an understatement really.
Bitcoin investing as secure as your worst security practices. Just like good ol' dollars. If you don't protect your credit and bank cards, someone will clean out your account.
You're only half right about shady exchanges. Turns out its not that difficult to avoid being a MTGOX clone. CAVirtex is a new Canadian exchange that is fully government compliant, professionally run (by actual businessmen) and not shady in the least. The trade volume pegs CAVIRTEX at #4 among all exchanges.
Sorry for being such a buzzkill.