In relation to the environment their ancestors endured, why was the Japanese Spitz bred to be a medium-sized dog?
Answer
To be small enough to live comfortably in urban or suburban settings
They were bred to be medium-sized—large enough to be substantial but small enough to live comfortably in modern, less agrarian, urban or suburban settings.

Related Questions
What was the primary intent behind the development of the Japanese Spitz in the 1920s and 1930s?Which characteristic of the coat was highly prized and deliberately selected for during the breed's establishment?What was the German Spitz ancestor traditionally used for?What inherent conflict exists between the Japanese Spitz's coat and its modern role?The relatively swift development timeline of the Japanese Spitz in the 1920s and 1930s suggests what about its selection process?Which two physical features were intentionally preserved to give the Japanese Spitz an alert and intelligent look?What temperament trait, inherited from its lineage, contrasts slightly with the expectation of a completely quiet companion animal?In relation to the environment their ancestors endured, why was the Japanese Spitz bred to be a medium-sized dog?What characteristic was actively screened against when selecting for the Japanese Spitz temperament?What role did the Samoyed, an ancestral type, fulfill that required immense stamina?What is the Japanese Spitz universally recognized as today?