Last time I looked I believe a few people live in Melbourne, Mildura, Albury, Noosa etc
I think the point is ENOUGH population, Mildura has a population of 30,000 roughly. 3 Flights a week in a 737 is 30,000 seats per year, so just from some marketing basics, you would have to carry the whole population of that town in one year to fill 3 weekly flights. Now if you operate AM/PM and well timed runs for business and professionals you will pick up regulars, commuters, that up that number, and yes holiday makers at appropriate times. But 3 random flights a week with no on carriage and you start to see the business case fall apart. Then try to say this will be viable to a destination that is not the major city for that town and the available patronage becomes extremely weak, like Mildura to Cairns or whatever other pairing they are talking about. You can't generate passengers that just don't physically exist, no matter how good your marketing is.