As has probably already been pointed out, small time users/growers routinely go unnoticed by authorities. The illegality of cannabis doesn't affect supply and demand at all. The harsh penalties here are dealt out to suppliers, with tough sentences and forfeiture of tainted money and property.
Cannabis has been identified as a problem in communities across the Territory. It is not a case of local/state or federal government saying it is bad, legislating against it and expecting a police action against users. Community elders and the majority of the community don't want this to be part of their culture, the same as alcohl abuse, domestic violence and petrol sniffing.