The answer lays in a different take on construction in general between Japan and Europe/US. In Japan, we tend to put a higher priority on efficiency and use a machine that is specialized for one function such as digging the ground or carrying soil. In Europe and the United States, people tend to prefer a machine that is multi-functioning. A backhoe loader is popular there for this reason, because it can do both digging and carrying. Also, usually the land is more spacious and traffic is less problematic in Europe and the United States, which makes storing and transporting a backhoe loader easier.

Backhoe loader [THE GREAT PICTURE BOOK OF CONSTRUCTION EQUIPMENT]