It is. Look what happened to GWS. They had to overpay a few "stars" to keep them at GWS to the point where they ruined their salary cap. Then look at all the players that buggered off from Gold Coast and Brisbane when they were poor. Melbourne and Carlton didn't have to worry about that level of players leaving when they were really crap.
It is harder for traditionally non-football states to keep players when the team is at the bottom of the ladder, meaning it is harder to rebuild.
We lost players when we sucked with players wanting to leave, and not many wanting to come.