That depends on the attitude of a certain person, one can also be greedy if he loses by doubling his bets trying to get back the amount he lose. It is greedy because in yourself you will not allow to lose and you want to end up winning all the time, that will not happen because gambling is a game where one can win or lose and there are days where we are unlucky so pushing the situation will just lead to bigger loses.
Everyone are the same, what differs is your stupidity when you play on the site. Sometimes people are just too stupid to realize their mistake while sometimes people can see through it. When people are too stupid to realize they keep on losing, they will keep on playing until they are broke and blame the site afterward
Well let me tell you first, if a person is greedy he comes to gambling to try his luck get rich in no time. Greediness is the one major factor of gambling and it cannot be avoided. But then its the greed that bring people to gambling and i have witness some normal people becoming rich within days because of high win on gambling while other very rich becoming poor again because of high loss.