A lot of the younger JD-PhDs, who do careful work that isn't very accessible to very many law professors, will never do well on law review citation metrics. As I think a comparison of your own mental list of whom the best quantitative social science business law professors are with a list of the most cited business law professors would reveal. But at the same time, my sense is that many faculties are pushing hard in a social science direction. What will happen if these trends continue? We could see the building of a professional elite whose work can't get arrested in student notes and survey articles.
Personally, I deplore the trend of which Zarig speaks. All too many of those "JD-PhDs, [whose] careful work ... isn't very accessible to very many law professors [and] will never do well on law review citation metrics," are producing work that is even less accessible to practicing lawyers, judges, legislators, and regulators. Their work would do even worse on a survey of citations by judicial opinions or Congressional committee reports than they do on surveys of law review citations.
Personally, I believe that law schools are hiring all too many JD-PhD's with middling law school credentials who really ought to be in a political science, economics, or sociology department but who don't have the chops in their home discipline to get a good position or simply prefer the higher salaries law schools pay. (As a local anecdote of what seems to be a widespread problem, I'm still annoyed at our appointments committee for having asked me what I thought about a number-cruncher who wanted to teach Business Associations despite having straight Bs in business law courses at Harvard. What I thought was not printable in a family blog.)
What we are seeing throughout the law school community is "the building of a professional elite whose work" is increasingly divorced from the practice of law and the process of lawmaking.
And, yes, I'm being uncivil and disparaging, as well as making sweeping generalizations, but, like the guy in Network, I'm mad as hell and I'm not going to take it anymore.
Update: Mildly revised to make clear I'm discussing a problem I believe is pervasive throughout legal education rather than localized to any particular school. Like, say, mine.