Its to pay for all the dumbarses in cars who create accidents in cages. Statistically it would be interesting to find out what the proportion of motorcycle accidents are that are created by brainfarts in cages. Compared to wipeouts of bikes alone. The only bad accident I've had is being knocked from my bike by a total cow who does not drive responsibly, i.e. look at where the feck she is going first. Hence the rego fee goes towards all those people out there who have been given the right to drive on the roads, but probably should not...