Existing securities laws didn't develop in a vacuum - they were a response to real problems in capital markets. Receiving something tradeable presupposes a counter party to trade with. Those likely will be in short supply once you've bought a lemon.
A secondary market which eschews many of the practices of the established markets vis a vis investor protections, and relies on information discovery and reputation, eventually will develop so much friction related to those costs as to stop being viable.
> Existing securities laws didn't develop in a vacuum - they were a response to real problems in capital markets
They were still developed in a vacuum. US securities laws are 90% promulgated by the SEC unilaterally, for quite some time, and even when Congress is involved the SEC still spends years warping the intent and implementation of the law. The SEC's public comment periods are a total farce and their decision is unilateral, doesn't provide more confidence in the markets, hampers interstate commerce, usually increases transaction costs and the cost of capital, and doesn't prevent scams.
A secondary market which eschews many of the practices of the established markets vis a vis investor protections, and relies on information discovery and reputation, eventually will develop so much friction related to those costs as to stop being viable.