But for those people who gamble just because they want to earn money, gambling will be detrimental to their small money left.
No way! I refused to believe your first paragraph. It's like you are saying rich people goes into business because they don't like money but because they just want to make the money, that's not true. Gambling is place primary for making money, any one can change their opinion but that's the truth and nothing but then truth. However, a rich person might be playing for fun and less motivation for money like the way a poor person would have in the first place.
If the casino are doing it for free, I'm sure they would by now be out of the he business, they are there to make money because they spend money on marketing to get your attention, they pay you when you win and they get paid when you lose and that's how it work continuesly until you either win them or you lose everything to them.
the house will never lose. period
they are the game makers
and in these kind of games they leave no loopholes
that is a given, will be different in such a small number of cases that I wouldn't bet on this.
but still possible for normal users to win in some cases...