Why does Rand equate "social metaphysician" with "second hander"?

For questions such as this, it helps to know a little about the history of Objectivism, going back to Ayn Rand's original periodical, The Objectivist Newsletter. The very first article on "Social Metaphysics" in the literature of Objectivism appeared in the November 1962 issue, and "The Argument from Intimidation" appeared in the July 1964 issue. The latter issue also included an article titled, "Social Metaphysical Fear." The articles that discuss "Social Metaphysics" and similar expressions were written by Ayn Rand's co-editor and co-publisher at the time (prior to their major breakup in 1968), and he probably retains copyrights to those articles. Probably to avoid potential copyright complications, it appears that Ayn Rand simply dropped all further usage of the expression, "Social Metaphysics" in her own subsequently published works, and relied on various other expressions, including "Second-Handers," to refer to the same phenomenon. It's also interesting to note that Ayn Rand's own writings on that phenomenon tend to emphasize a broad philosophical perspective, while the writings of her former associate tend to emphasize motivational psychology (probably because that was his main field of study, in relation to Ayn Rand's phlosophy of Objectivism).