Hi,
Yes, they were very popular in Germany after the war.
The country was bombed to smithereens and most factories able to build any kind of vehicle were just piles of rubble.
Also due to the fact that through centuries of inheritance most farms only consisted of a few small fields, these walk behind tractors were used by those small scale farmers who worked from 6am till 4pm in the factories and then rushed home to tend their farms.
Besides, these walk behind tractors were the only thing affordable and obtainable in those days - they also did not consume much fuel which was also rationed in those days IF you were lucky enough to find a gas station with operating pumps.
Another bonus was that most of the old horse drawn attachments such as mowers, hay rakes, ploughs, harrows and wagons could be adapted to these little all rounders.
Because of their limited track width, they were highly popular in the vinyards where heavy machinery was of no use.
In the Alps they are still used today for mowing steep hillsides(up to 60