After the military success of the Jeep maybe there were to many models left over so a lot of people had access to them. Or maybe those who returned from the world at war found the capability astounding and wanted to have one. Or the surplus made the price attractive as a good means of transportation.
Whatever the reason the Jeep CJ model was born and it was the beginning for the legacy of Jeep to the mainstream population. It quickly became popular as a fun recreational vehicle with its top off fun access. The Jeep CJ 1942-1986 models jump started the Jeepin lifestyle and ushered in over 70 years of Jeep fun.