That’s not entirely the truth. According to George Mackay and the Japanese, who were still recording the practice well into the 1920s, Han immigrants of all ethnicities did it, and they did it because they believed it was a medicine against malaria.
Those Aboriginals who already agreed to Sinification would actually lure other Aboriginals out and capture them for cash.
Sometimes the savages are taken by the treachery of their kinsmen, the Pe-po-hoan. One famous old chief was on the top of a mountain with a band of twenty-four braves, when he was beckoned by a party of Pe-po-hoan to approach and drink one another’s health. After much hesitation, the savages came; but hardly had the liquor been tasted when the crafty design was revealed and the savages attacked. After a desperate hand-to-hand struggle the men escaped, but the chief was taken a prisoner. He was handed over to the Chinese authorities, who gave a reward to his captors. After being imprisoned, beaten, tortured, he was dragged through the streets, and women rushed forwards, thrusting long needles into his flesh by way of avenging the death of their husbands, sons, and friends. When the signal was given for him to kneel, with diabolical glee he said he was not ashamed to die, for at his house on the mountains was a row of Chinese heads lacking only six of completing the hundred, every one the prize of his own daring skill. …
From the page of Mackay’s memoir that talked about Pe-po-hoan’s trap for their kinsmen. The next page went into the gruesome execution of the old chief and how people fought over his flesh.