So I can understand, what do you mean by "the merits" (in basic terms)? You think people don't like the concept of being able to invest a bit of their own money for retirement?
Not when it just offsets your benefits from the balance of the system, at a rate of 3% above inflation per year. It is a scheme akin to investing in stocks at 100% margin. It just won't happen.
The purpose of insurance is to assess premiums over a large enough base to cover risk. When you allow some of the premium to leak out it is no longer insurance.
Americans are smarter than that.
BUMP