Want to know why Europeans buy smaller cars? It has less to do with customer demand, and everything to do with how the infrastructure was built over the past 60 years.
In older cities and towns, they're extremely space constrained. All of their infrastructure is built on a narrower gauge than what is used in North America. Lanes are narrower, turns are tighter, garages are smaller, and roof clearances within structures are shorter. Even their semi trucks and trailers are physically smaller.
Now, that said, I have seen F150's in France on occasion. They have to take 2 deep x 2 wide parking spaces when they go to the supermarket And the F150 isn't exactly what I'd call a monster truck. My longbed Dodge 2500 would have been impossible to drive there.
A Jeep Cherokee or Liberty looks like a Hummer when parked next to all those French, German, and Asian cars. And neither of those is what I'd call a full size SUV. My Honda minivan would be bigger than a commercial delivery van.
Go to Australia, and you see more fullsize vehicles. But that's because they built to a slightly larger gauge.