This is true but i know a small amount of people who do well as pro gamblers..
A small amount of people make excellent statisticians and natural mathematicians, some people are gifted with the ability to walk a tight rope and juggle throwing knives and other high risk activities. Its such a small amount of people, requiring much skill, discipline and training over many years from an early age even that most of us wont qualify for such things. The smart thing to realise is when dealing with risky tasks is you are extremely lucky to win and be glad at that much, keeping track of all the odds in your head and making it so you come out on top money wise is harder then it appears
The OP is wrong, not everyone loses in the long run but its easily arguably a majority of players