Your view on this is correct, winning isn't negative but what you do next would determine whether you would have a negative or positive result...some gamblers win and the next thing they think of is to try again, this is just as a result of insatiability and greed... winning comes with an excitement that if not properly controlled it can make you get carried away... That's why it's important to be in control as as a gambler
It's actually funny for gamblers who have won and then try again to get another win. Gambling is indeed to get a win, so when you get it, why not enjoy it?
Dissatisfaction and greed may be factors, but I'm sure gamblers who do it must be addicted. Because the victory obtained has not satisfied their desire to gamble. Even though they return to gamble, at least they have to feel the victory and leave a little to continue.
Greed is the reason people never get satisfied with the win they make irrespective of the fact that it doesn't come always. Most people like to believe that any instances of them making a slight win is their lucky hour so they'll want to maximize their luck but unfortunately luck doesn't work like that, and we cannot determine or know when we're gonna get lucky, which is why we need to treat every bet thesame without letting emotions get in and reap us from making the right decisions of a good risk management strategy.