Part of that comes from living in the shadow of more popular codes. Some of it is because of the various political schisms over the years. For instance, when the breakaway ethnic clubs established the State Federations, scant regard was given to the records of the bodies they had superseded. More recently there is a tendency to be ashamed of our history, wanting to lock it away in the attic like The Simpsons did with Bart's evil twin Hugo.
In the pre-internet age, reading about football was pretty limited. There were weekly newspapers covering local competitions with overseas results, and Shoot! magazine which would arrive on our shores three months after original publication. Second hand bookshops were a good source of British books about the game, many of which followed a similar structure.
Most football fans will know a bit about the history of the clubs they follow, the great eras and players. In Britain, this extends to a larger folklore of the game that is still maintained by followers of the modern game. The staples of this are repeated in the many guides and histories of football contained in those books.
There is the White Horse Cup Final, Bert Trautmann going from German prisoner of war to winning the Cup Final for Manchester City playing with a broken neck and the tragedy of the Munich Air Disaster. The name of Sir Stanley Mathews, the Wizard of the Dribble, lives on generations long beyond anyone who actually saw him play. Enormous goalkeeper William "Fatty" Foulke, Dixie Dean's amazing goalscoring, Herbert Chapman's great Arsenal side, the Tottenham Hostpur double winning team, Real Madrid dominating the early years of the European Cup and Ferenc Puskas destroying England at Wembley are known by all.
Beyond Joe Marston playing in the F.A.Cup Final for Preston North End and the 1974 Socceroos, Australian football folklore is almost non-existent. Throw in three random names and Reg Date and ask a fan to name the Australian football legend, are you likely to find more than 25% of them getting the answer right? I'd highly doubt it. Can any name a single Australian footballer from pre-WWII?
It's a sad situation, sadder still if it is never improved upon because of a need to dishonour the past in order to make the present seem greater.