Maybe I would say that you are discussing two types of gamblers here, where the first is those gamblers who have entered a cycle of addiction so that it is always difficult for them to stop in any situation, win or lose. And the second is the gamblers who from the beginning have understood what and how gambling really is so that they know what to do in every situation such as stopping at the right time, especially taking a break when experiencing defeat.
I think we can judge which is better of the two types of gamblers, and clearly the second is much more recommended, or what is meant is being a gambler who understands in general what gambling is and how winning and losing work is something that is more recommended for a gambler to have, because only by having this proper understanding will we avoid various significant negative impacts.
In fact, with gambling, everything is almost the same as with trading, where a small percentage of players remain with a profit, different sources claim differently, on average from 3 to 5%, in fact, this is not much. But I think that there are significantly fewer professional gamblers than traders, and I think that players risk less money than traders, because the risks are also different.
In your example, both the first and second should understand the danger that is in gambling, if their goal was to double the deposit and withdraw the profit, and in the end the player only gets losses, then it seems to me that with proper risk management it is difficult to get addicted, most likely the player will simply stop playing, when he will lose part of his deposit. There is no point in continuing if instead of doubling, he received a significant reduction.
Never ever i do consider out on making some comparison in between trading and gambling on which yes both things does have that kind of risks involved on the time that you would really be dealing up with it but the level of certain risks would really be that totally different to each other. You cant be able to compare entertainment/leisure into something like investment/business which you can find in trading. Although when it comes to the chance and probability on making money then both things could really give out such chance but on the different approach.
Speaking about quitting on the moment that you have doubled your money then this is something that not would really be simple. Why? people would really be having those thoughts that they could be able to do it even more on the moment that they do become that confident about their condition on which they do believe that they would really be still lucky on their next rolls.
On the time that you would be losing then this is the start on chasing up those loses again and the cycle would continue.