derivative market being gambling.

WRONG. The derivative market DOES perform a number of economic functions.

First, prices in an organized derivatives market reflect the perception of market participants about the future and lead the prices of underlying to the perceived future level. The prices of derivatives converge with the prices of the underlying at the expiration of derivative contract. Thus derivatives help in discovery of future as well as current prices.

Second, the derivatives market helps to transfer risks from those who have them but may not like them to those who have appetite for them.

Third, derivatives, due to their inherent nature, are linked to the underlying cash markets. With the introduction of derivatives, the underlying market witnesses higher trading volumes because of participation by more players who would not otherwise participate for lack of an arrangement to transfer risk.

Fourth, speculative trades shift to a more controlled environment of derivatives market. In the absence of an organized derivatives market, speculators trade in the underlying cash markets. Margining, monitoring and surveillance of the activities of various participants become extremely difficult in these kind of mixed markets.

Fifth, an important incidental benefit that flows from derivatives trading is that it acts as a catalyst for new entrepreneurial activity. The derivatives have a history of attracting many bright, creative, well-educated people with an entrepreneurial attitude. They often energize others to create new businesses, new products and new employment opportunities, the benefit of which are immense.

Sixth, derivatives markets help increase savings and investment in the long run. Transfer of risk enables market participants to expand their volume of activity. Derivatives thus promote economic development to the extent the later depends on the rate of savings and investment.

Derivative market serves a big function in letting company to hedge their risks, e.g. company having an AUD assets and wants to hedge the AUD risks. Then, they can enter a simple AUD forward deal.
However, derivative is something that people can be very creative and the regulations cannot match up with people's creativity. Some people find that derivative can be a way to gamble. Since there are too many people gamble in derivative and make derivative market like a casino.