The Aborigines found themselves in a situation were they were systematically assimilated into a new culture without being able to do anything. The children where taken away from their parents, and they were raised by people that were of British descent or were educated in British based institutions. That led to the children learning only what their British parents and institutions were teaching them, thus not being able to preserve anything from the Aboriginal culture.
Also, there were forced marriages between the British settlers and the Aboriginal women with the purpose of ethnically wiping out the Aborigines in few generations. That was one of the worst methods that has been used for destroying indigenous people.