Scams happen even in supposedly highly regulated financial companies you only need to look as far as Bernie Madoff and Jon Corzie's MF Global this doesn't really have much to do with regulation.
I believe in bitcoin and its long term potential, but there is no question that lack of regulated exchanges will stunt its long term acceptance.
That just isn't true. Bernie Madoff got away with his outright ponzi scheme for nearly 10 years before being caught. Individuals expressed concern to the SEC about Madoff's investment fund as early as 1999. The SEC didn't do anything until 2009.
The scam was told to be $65B, but the actual losses were ~$17B and they have recovered more than half that (over $9B). Additionally the IRS let the losses be written off, so you and I ended up picking up another half of that tab.
tl;dr it was an awfully large scam, but not nearly as large as most think. Less than half the value of an instant message client actually and only a few Instagrams.
Good regulation implies preventing fraud through rigorous rules and monitoring before it happens or if it does before it gets out of hand to the point of needing to resort to the courts.