I think it's at least as much Murray ruining goalies, including Holtby, as Korn being a goalie whisperer (which he definitely is). But Holtby also had great development and progression and early results under Dave Prior, then Oates-administration came in and drove Prior out after 2013, and then spent the next season overruling the new goalie coach (Kolzig). Korn was able to revive Holtby's career and take it to its full potential, but I do think Holtby under Prior would have been a very successful goalie as well (albeit perhaps without the Vezina peak).
Prior then went on to follow George McPhee to Vegas, where he revived MAF's career and took it to new heights as the Director of Goaltending. He was eventually ousted in Vegas as well (sometime around the time of the Lehner trade).
Why the hell the organization has stuck to Murray when Dave Prior is available to be hired is absolutely baffling.