This isn't entirely correct. Regulation D also includes requirements that the investor be knowledgeable and experienced enough to evaluate the potential risks

This isn't entirely correct. Regulation D also includes requirements that the investor be knowledgeable and experienced enough to evaluate the potential risks and rewards of the investment, and be able to tolerate those risks. However, the net worth/income test is a pre-requisite. Now, in practice, an investor's knowledge and risk tolerance are usually established by signing a piece of paper attesting to such, or at most by having the investor check "YES" in a check-box.