Some peoples seem to have feared the dead and so they wanted to get rid of them. More sophisticated people, like the later Greeks and Romans, who greatly favored cremation, seem to have been guided by philosophical views that downgraded the body in comparison to the spirit. Just about all the ancient philosophies had little use for the body. In general, cremation does reflect a low view of the body after death, however one may view the fate of the liberated soul. I took the liberty of checking out various websites advocating cremation on the internet and, to my surprise, the only incentive I saw listed was economic.
Cremation is cheaper than burial.
But I think there is also a new age mysticism that motivates, however vaguely, renewed interest in cremation today. The other day I ran across a touching story regarding the spreading of a loved ones ashes. The man who had died was a mountain climber and his friends carried his ashes to the top of Mt. McKinley, the highest spot in North America. That is no small feat and it surely expressed real devotion. With great reverence, the friends observed a moment of sileence, after which they let his ashes go so that his spirit could float above the mountains.