With great respect (and I mean that), the Perth media has less to cover. Two x AFL teams, 1 x A-league, 1 x Big Bash/cricket, 1 x Super Series, 1 x netball and 1 x NBL and WNBL. The parochialism angle is easier to take - and there is less sports news than on the eastern seaboard. Believe it or not but the time difference helps with this as well. You cannot just take as many eastern seaboard stories on delay as say Adelaide does and get away with it.
Adelaide get more media coverage than the big market teams as well. They still have, as I understand, a FT basketball reporter and they certainly get TV news coverage.
Melbourne has 10 AFL teams, Storm, Rebels, 2 x Big Bash, 2 x A-league, 1 x netbal1 and 1 x NBL and 3 x WNBL. Add to that the busiest major sports event calendar of any major city in the world.
The sports director/editor has choices to make, and they are much harder in Melbourne than in Perth or Adelaide. Fact is the Herald Sun is built on AFL coverage.
No question booming crowds are helping the quest for media in Perth as well, along with fascination, and disappointment, in the new venue.