I don't find it completely implausible that some people with influence in the lawmaking process (whether it be congresspeople, their advisors, or interest groups) have the historical knowledge and analytical ability to develop a perspective like Michael's.

Why should one assume that the actual reasons behind a policy are the same as the stated ones?

Even more, if these facts about the effects of the policy are true and important, then whether or not they comprise a large part of why anyone wants or says they want the policy isn't even that relevant.