In my opinion, the main reason is the syndrome of over-expectations from the casino. Many newcomers, probably under the influence of movies or TV series, believe that gambling will make them millionaires and do not know how to take defeats. They are sure that only some absurd obstacles prevent it and constantly repeat their own mistakes again and again, without drawing any conclusions from their bad experience. Read an interesting theory about it:
The Hungarian psychoanalyst Sandor Ferenczy put forward an explanation that has come to be called the "hypothesis of infantile omnipotence." Ferenczy thought that the very small child did not know about his helplessness. Lying in a crib, he controls the behavior of adults by commanding them to feed, change and entertain a little tyrant. With time, as the child learns to walk, falls and bruises, the illusion of omnipotence begins to dissipate. Most of us lose our sense of omnipotence by the age of 6 years. But from time to time it comes back to life - for example, during a game when a player falls into the illusion that he can guess the numbers that must fall. Anyone who has ever played in a casino or a stock exchange knows this feeling of absolute confidence, which is an echo of infantile omnipotence.