Australian snakes are as poinsonous as they are, in order to sell more of the serum, Victoria Bitter.
VB can also be taken as a preventative measure, and should ideally be taken by the gallon for it to work effectively if bitten by a snake. It wears of rather quickly, though, and therefore need to be taken on a daily basis. XXXX works good to, but not exactly as good.
On a more serious note, I guess its actually because the Australian species have been geographically seperated from the rest of the world for much longer than the other species has been seperated from each other, and severe toxicity is just the evolutionary path they took, what with having a more restricted gene pool and smaller numbers which enhanced the speed of the evolutionary process by a factor of x.
