There is no point for any gambler to even be studying their chances of winning in any game. It is a game of luck and any gambler that does not already know that the chances of winning is far lesser than the chances of losing, then such a gambler is not ready to start facing reality and until he is able to, he might end up being an addict. A good gambler should know right from the onset this is just a game, which you can win or lose big, so be ready to accept the outcome.
Actually there is and that is so that they can go back to reality and know that gambling was made for the casino owners to make money. This is why for me a good gambler is someone who have learned their lesson and stopped gambling completely. Sure, some might be able to set their limits of how much time and money they are going to spend in gambling. But to me that's just them justifying their bad habit which is gambling. There are gamblers that say they are gambling but it's completely fine because they can stop whenever they want. But to me it extends from being able to stop gambling, to being able to use that money and time for a better purpose. You have the capability to stop the bad habit, yet you are not doing it. Thus, the capability is wasted.
I don't think what you're describing is necessarily a good gambler at all. I think that's just a gambler who's aware of the risks and chances and are ready to face the consequences of it, which quite frankly is almost every gambler. Right when they deposit the money, they know that sooner or later they are going to lose it because they know, from experience and from theory, that they are going to lose.
A good gambler is aware that gambling is nothing but a way of losing money. They are the ones who understands the gambling industry so they have already left.
I agree with you in general, but there is a third option. I mean, you've described two of them, either trying to make money with gambling(which is not the best idea) or quitting completely(which is hard to do for some people because they enjoy gambling). The third option would be to continue with realization that you can hardly earn money with gambling, but that you still can get your entertainment from it. You just have to decide how much you can spend on it, say, per month, and never go over that limit. Of course, if you unable to control yourself, you should quit, that's true.