The American Constitution Society's blog quotes the Chief: “Pick up a copy of any law review that you see, and the first article is likely to be, you know, the influence of Immanuel Kant on evidentiary approaches in 18th Century Bulgaria, or something, which I’m sure was of great interest to the academic that wrote it, but isn’t of much help to the bar.”
The C-Span video is here.
The Chief's views are not new. Legal scholarship has moved away considerably from doctrinal case-crunching and the primary audience that law professors write for is other academics. To be sure, some legal academics do write case reviews and other valuable doctrinal material. This is especially the case in jurisdictions like Ireland, where legal scholarship is still evolving. But the implicit assumption in Justice Roberts' view - that legal scholarship has to be "relevant" to legal practice - runs counter to the objectives of contemporary legal academia.