They creamate their dead because they have done so for thousands of years. It is an efficient way of getting rid of human remains, both for nomads and for people living in heavily populated areas.
The idea that this custom has anything to do with reincarnation was introduced much much later and then in folk Hinduism only. Reincarnation was instead a Dravidian idea that Indians picked up when Indo-Iranians arrived on the Indian subcontinent.
This is why you find no belief in reincarnation in Iran or in European or Central Asian Paganism.
2009/10/11 Zaneta Garratt
Hi Georgios, Alexander and Clint,
while on this subject-
The Hindus cremate their dead because they believe that it helps to release the soul which is then reincarnated-
Then there is in Hinduism also the god Yama who appears first in the Rig Veda and is seen as a mild personality in the beginning but later on he takes on some more scary traits-below are some references-
Yama (Sanskrit: यम) is the lord of death in Hinduism, first recorded in the Vedas. Yama belongs to an early stratum of Indo-Iranian theology. In Vedic tradition, Yama was considered to have been the first mortal who died and espied the way to the celestial abodes, and in virtue of precedence he became the ruler of the departed. In some passages, however, he is already regarded as the god of death.--- Yama is a Lokapāla and an Aditya. In art, he is depicted with green or red skin, red clothes, and riding a water buffalo. He holds a loop of rope in his left hand with which he pulls the soul from the corpse.
In Vedic tradition, Yama was considered to have been the first mortal who died and espied the way to the celestial abodes, and in virtue of precedence he became the ruler of the departed. In some passages, however, he is already regarded as the god of death. Yama's name can be interpreted to mean "twin", and in some myths he is paired with a twin sister Yami
YAMA. In the earliest Ṛgvedic hymns, Yama is a benign god who looks after the well-being of the dead, whom he entertains with food and shelter. His abode and its environment are pleasant and comfortable; survivors supplicate him for the care of their departed relatives.