I can agree with you that gambling for the purpose of doubling up means definitely moving to the downside. There is doubt whether a gambler can survive in gambling but if we want to double our profit or balance from that position then it would be a big mistake. Also in gambling we can never be sure so how we will be able to increase our balance by 2x? Yes if we are lucky we can increase our profit several times. If someone gets lucky in gambling and wants to take a break from his gambling it is entirely up to him. But gambling with profit motive is more likely to lose.
If they can double their money from gambling, I am sure many people will try to playing gambling and even they will spends much money to wins big money. But that will happens as they wants because gambling can makes them lose much money if they don't have limitation.
It is right that if we wants to double our profit, we can lose much money because we will not see that we don't have a big chance to wins more money. We will not stops us from playing gambling instead will continue chasing the wins and that can cause us lose all of the money.
We can only double our money if we have luck and we don't know when we will see our luck comes. Rather than spends much money to wins, it is better we still limits our money and enjoy the games so we don't have to lose much money.