Rob, I think you are unduly focused on how a photograph is made, a process, rather than end-result. For me, it is the end-result that determines the creativity or artistic impact, not the process. Ultimately, it is the viewer who perceives it as art or creative, and he/she does not necessarily know or care how much effort went into it.
Ultimately, it is the emotional impact the end-result creates, and a landscape can have it just as much as any other genre (at least for some people, though not you and Russ). You call Kenna's landscapes "dull", I, however, call them sublime, zen-like and they deeply affect me on an emotional level.
Russ would accept landscapes only as a background for humans... I would dare to suggest that landscapes are anyway ultimately about humans, even when they are not directly present. Viewers are, however, always present, and they project their emotions into the image in front of them. What I see in Kenna's work is desolation, solitude, "splendid isolation", quiet desperation, subdued elegance, etc., and it all speaks more about me, of course, making those "dull" landscapes ultimately very human.