If they all would be broke there wouldn't be any gamblers. Winnings come with the territory as same as losses. That's why people gamble. They wouldn't get addicted or gambled at all if they didn't win as well.
Yes, but in the long run gamblers lose more than they gain. The incentive to gamble is that every now and then, in some sessions, they come out positive, but the sum total of their lifetime bets and winnings comes out negative.
Some people just don't have any risk management and they don't cut their losses but gamble everything. These people would gamble on high leveraged markets is there wasn't slots around.
In this I agree and I have said it before: those who have problems with gambling, if gambling did not exist they would have other problematic behaviour such as the one you are talking about.