Germany also has lots of pavement and hotels. They have a lot less opportunity to off-road. However, they get a lot more vacation time and it's not unreasonable to drive to Africa or eastern Europe. Both places offer lots of off-pavement driving, as well as cultural exploration opportunities, so many people take travelling vacations. And they usually take their kids with them.
In the US, most of the really great places to go... say Yellow Stone, Grand Canyon, etc. have restrictions on off-highway travel and have large car-camping or RV facilities. So there's no need or use for an "expedition" rig. That leaves recreational 4 wheeling. That has evolved to be more and more hard-core, guys pushing more and more, looking for harder challenges. It can often be not safe for kids so they get left at home, and doesn't allow for carrying much gear. People go for a weekend, or a week at best.
There are opportunities to travel to Mexico, or even into South America, but statistically Americans are less likely to travel abroad in the first place.
Canada is similar to the US with a few differences. We have VAST tracts of wilderness we could travel, but there's not much cultural exploration. If you go north on the resource routes, there's a lot of trees and water, trees and water, trees and water. It can get pretty boring. We also get vacation time somewhat more than in the US, but not near that in Europe. You could go north for a week, but beyond that... takes a special type of person to want to do that. Staying closer to civilization, again, there is no need or use for off-road equipment. Canada is more similar to Australia in a way, however, there are pockets of civilization to visit in Australia. Not so much in Canada because of the difficulty of travelling 9 months of the year. For example, it would be really interesting to visit indian or inuit villages up north, but there are no roads going there. You can't get there from here.
Europeans tend to travel abroad for cultural exploration in places where there are no paved roads. In North America, recreational 4 wheeling IS the culture that many people go for. The differences in setups reflect that.
I don't mean this to be taken in absolute terms. Just a generalization to explain the differences in the markets.