I found out why deleted scenes are deleted. There were a total of five such scenes:
1) A badly written piece of dialouge between Mel Gibson and his brother.
2) Two Flashbacks which really didn't further the plot.
3) A scene with a burnt dead bird on the ground which was actually better explained by some dialogue in the movie.
4) A scene where Gibson remembers dislocating his brother's arm. It made sense when he was remembering his children's birth but not this.
Conclusion: Scenes are killed mostly so we don't waste six minutes of our lives watching totally irrelevent things. And if we really want to, we can wait for the DVD.