The point is that with public securities, the SEC makes sure that it's not a scam. A public company can't just decide one day to issue a ton of stock and hand it over to an arbitrary entity, there's a regulatory process and legislated veto power held by the shareholders/board.

When you buy an unregulated security (like shares in a "crowdfunded" startup), that's the protection you're not getting. Most people in this community tend to see the SEC as the enemy, but this is the value it provides.