The Moriori were Maori who settled the Chatham Islands, an isolated group of Islands East of the South Island but part of New Zealand.
because it is part of the maori culture and they are important to new zealand and they are well known to new zealanders. they are very very well known just like god so there you are....
The name Moriori is given and belongs to the first peoples of the Chatham Islands, (Moriori: Rekohu, Māori: Wharekauri). These peoples descend from early Maori settlers in Aotearoa. Early mistaken scholarship produced the 'Moriori Myth'.
The Moriori are the Maori inhabitants of the Chatham Islands and their descendants still live there today. In 1835 war parties of Taranaki tribes Ngati Mutunga and Ngati Tama were brought to the Chatham Islands by European ships. In their isolation from the mainland the Moriori had developed a pacifist society so were unable to defend themselves from the violent assault by the invaders. The Moriori were variously killed, eaten and enslaved.