Interesting idea, Ulrich, but I must say that it is the complete opposite of the way I think about these things! :rolleyes:
When I look at a landscape for photography, the thing that I try to find is that particular something that most distinguishes that landscape from any other. Indeed I am usually drawn to the relationship between the sky and the land, and I suppose that is a general theme for me per your definition, but what attracts me is how differently the common elements like sky and water and foliage interact.
What I find the most gratifying is to take a shot and print it and later relive my feeling of being at that particular place through the print.
So, the way I see it, the whole power of photography is its ability to record particular perspectives... at particular moments.
The flip side of this approach is that a photo may hold absolutely nothing in it for most people who see it- it may be as foreign as a place they've never visited. That is fine with me, fortunately I'm not in it for the money Though I do see your point that there must be some general "hooks" in the photo that draw people in, if it is to be "successful."
To be blunt, I think that a highly general photograph, as you describe it, sounds to me like a successful stock photograph... Seriously, isn't that what makes stock sell? That it has mass appeal because almost anybody can "get" it?