Because of greed, fear and ignorance
As soon as people understand the Buddha’s teachings, they realize that a pure heart can protect them much better than bits of paper, bits of metal and a few chanted words and they no longer rely on such things. In the teachings of the Buddha, it is honesty, kindness, understanding, patience, forgiveness, generosity, loyalty and other good qualities that truly protect you and give you true prosperity.
I know a person who makes a living selling lucky charms. He claims that his charms can give good luck, prosperity and he guarantees that you will be able to pick three numbers. But if what he says is true then why isn’t he himself a multi-millionaire? If his lucky charms really work, then why doesn’t he win the lottery week after week? The only luck he has is that there are people silly enough to buy his magic charms. ~ by Venerable S. Dhammika