Ian and AgX are right. There is a difference within countries, too. The East Coast of America, the West Coast, and the great Midwest are all different. Sometimes I wonder if the Eastern Establishment realizes that there is civilization between the Mississippi River and California.
I'm sure they do. Some of the best landscape photography is produced in the East and Midwest, surely.
But I think that the presence of cultural diversity is also a cultural thing.
I live in a small country, Sweden, which has a lot of ethnic diversity nowadays due to immigration. But cultural tastes are still pretty homogenic.
Artistic photography as had a huge upswing in recent years. Most museums and galleries do multiple photographic exhibitions each year, and they get big audiences. I think it's because photography is more accessible than other forms of fine arts.
But still the national photographic scene is very consevative. Most domestic photography is very formulaic and sticks to traditional ideas on composition, exposure and choice of subject. You could say that it's an emphasis on "nice" photography, rather than bold, expressive or personal imagery.
For comparison, I saw a Cindy Sherman exhibition at the Museum of Modern art a few months ago. Even though, most images were staged "selfies" each image carried a massive emotional content, much like a punch in the head or stomach. My companion and I actually had to take a long break in the middle of it because it was almost exhausting.
She was one of the foremost pioneers who established photography as an accepted artform for expression, not just documentation, on par with painting or drawing.
We don't have that in domestic photography, even people who try to be gritty end up bland because they don't create a correlation between the subject and the technique.