Gambling is addicting because it is a way for you to earn money without any skills required. Unlike other methods of earning money, you need to have qualification and knowledge, gambling dont. However, they dont want to know that gambling also make you lose instead of win.
Its not that they dont want to know, they know but they simply dont care or their emotions take it out of their systems. They will keep on betting like addicted gamblers and end up becoming beggars.
However I blame the people's greed to make easy money the only reason why gambling makes them addicted.