Because they won the most premierships
St George
They play in the NRL - not the AFL. But they havent won any NRL premierships either.
The South Sydney Rabbitohs and the Sydney Roosters are tied for the most NRL titles, with each team having won a total of 14 premierships.
The Wests Tigers have won once and the Balmain Tigers now defunct have won 11 times. As of 2010.
East Fremantle with 29 premierships
As of May 2011, Essendon and Carlton share the honor of having won the most VFL/AFL Premierships with sixteen apiece.
Melbourne has won 12 premierships
Which AFL team has won 10 premierships
No NRL coach has ever won three premierships with three different teams. Plenty have won two with different clubs (Wayne Bennett, Tim Sheens, Phil Gould, Chris Anderson etc) but none have done it with three clubs.
The Boston Celtics with 17 Championships.
Hawthorn have won ten Premierships. The years that Hawthorn have won, is in: 1961 1971 1976 1978 1983 1986 1988 1989 1991 2008