You mean like North and Friday Night Football?
This a poor poor argument and it seems to be everyone's response to "We built it we should keep it".
North did pioneer the idea, however:
1) They didn't pioneer the idea exclusively with another club, it was necessarily shared around as they needed another club to play against. Collingwood v Essendon does not require this.
2) This became a weekly occurrence, and hence for fixturing reasons it became impractical to have North v x every Friday night. No club reasonably would expect that to happen. ANZAC day is once a year and hence does not require this.
3) Television controls much of fixturing. North have a very small supporter base and cannot get people to the game, or to watch it on television. Collingwood v Essendon consistently draw 85,000+ to the games with many more watching it on television. Hence, ANZAC day does not require a change to satisfy television.
4) Collingwood and Essendon do not receive financial handouts from the AFL as every other club do. In fact, Collingwood play games away every year in order to help other clubs financially (every year at ANZ stadium, Queens birthday etc.). There are no calls for these fixtures to be rotated, when we are brining money into your pathetic club.
5) ANZAC day as a Collingwood v Essendon match has become a tradition between two of the biggest Australian sporting clubs. The fact that it is played on a traditional day between the two biggest clubs is what continually draws numbers. If you were to rotate it on any level (except perhaps between Carl, Coll, Ess) you decrease the history and tradition, and take away the fact that it is between the two biggest clubs. Therefore you have created a game that is has no tradition between two of the smaller clubs. You would not draw fans.
As long as we draw 90,000 I don't even see why we argue of this, because the AFL will not take that away.