I think that the segment is a key factor in this arena.
I know of many landscape professionals still using film. In particular, the Panorama shooters using 120 film for 6x17cm images. Nothing (including the Seitz digital) comes close to the quality and enlargement possibilities of a well exposed piece of Velvia in this segment.
Also, large printed B&W landscapes, IMO, are still best shot on LF (or ULF) film. Is there anyone out in the digital world producing the quality of, say, Clive Butcher? I think not...