also, a lot of people " chase" when they are down, thus losing a lot of money when they hit a bad streak. when they win, they usually keep wagering the same amount, so they dont win huge when they go on a winning streak.
Seems to me you are suggesting that "streaks" exist. They don't, but "chasing" does have a harmful affect. When people lose and increase their wagers they are increasing their turnover and this causes them to lose ev at a higher rate. The reason why problem gamblers lose is because they fail to have an edge and gamble enough for the long run to be significant.