It's weird, and very telling, that a SCOTUS Chief Justice feels the need to publicly justify his actions in a majority opinion. (Soon after another justice preemptively attacked a critical ProPublica report by using the WSJ as a forum.) This is NOT a normal Supreme Court!
What Roberts wrote: "It has become a disturbing feature of some recent opinions to criticize the decisions with which they disagree as going beyond the proper role of the judiciary,"
What he was thinking: "We have a majority now, and we'll bloody well go as far beyond our proper role as we want. You can't stop us, ethics and precedent be damned!"