If you quit that's when you lose is the loser mentality, in my opinion.
To me, that's more of an intense gambler that doesn't have the time to think of quitting. But then, losing will make him realize that there's a need to rest and they can no longer uncuff the chain that has strangled them.
So many gamblers have lost life savings before on gambling to chase losses and that is how they thought about quitting gambling. I don't recommend applying this logic since there is no guarantee the next big multiplier will save all previous losses while you can add up more on the loss side. Gambling is all about the fun and nothing else, so forget this point of view and don't chase losses.
That's for real.
Those that don't realize that everything is taken from them has probably the ideology that when they quit, they're all losers. Well, we're all losers in different senses and from the different battles that we're having, and not just with gambling. Stopping and realizing your losses does make you understand that you're not doing well and you need to stop but that doesn't mean you're a total loser.