Yeah but the question is why they get carried away. I think loneliness could play a big part in that, because, why would you spend much time on gambling in the first place if you have good social relationships in your life?
There are lots of gamblers who have a healthy social life but still addicted to gambling. I don't see that as a reason why should a person will refrain from doing gambling. Again take note that we are talking in general here so reasons are vary per person.
The feeling of winning big amount is one of the reason why people loves to do gambling. Since winning in gambling is not the usual case and scenario, there will be lots of attempts that will be made just to get that purpose. And the result? Gambling addiction.