Jackaroo is an Australian term for a trainee farmhand, so it could be that the perceived market was outback sheep and cattle stations needing a simple, rugged aircraft for getting around the property,doing odd jobs and taking the kids to school?
With De Havilland Australia producing the Drover (named after the Australian equivalent of a cowboy), and Jackaroo inferring a small or junior worker, the inference is that it would be something smaller and cheaper to run.