To be honest, at the beginning when a newbie starts gambling, he probably just tries it as fun. Some would be different, but most newbies consider it a fun pastime. But slowly they become addicted, and they don't realise that when they become addicted actually. I have seen some serious addiction togambling recently. He borrowed a lot of money from friends and family, but he really doesn't regret it. He isn't trying to return the money and just considers gambling.
Your are right when a newbie Start gambling he or she probably try it fun, myself for example when I was first introduced to gambling I started trying it out for fun and I was winning and losing until one when I became serious with it. So I was not longer trying it out fun rather to make profits, but I was never addicted to it even up till today I still gambling for fun and with the money I can afford to lose. Normally there are ways you will approach gambling you will slowly become addicted to it and start borrowing money and selling properties just to get money to gambling. Although gambling is not a bad thing but when you get addicted to it then become problematic.
I pretty much agree gambling is for rich people; whether they win big or lose big, they don't have to beg from others. They could feed their family without troubles, unlike poor addicted gamblers. Rich people won't consider gambling as a source of income; they must have other businesses to survive. However, no one can control the luck, so you have to think about it and make a strategy to manage the risk.
I disagree with you here, because gambling is not for the rich people only, I know wether the rich win big or lose big it's not a problem to them since they don't have to beg from others to feed their family, but that's not mean that the rich don't beg among themselves. And can agree with you on your second paragraph that the rich don't consider gambling as a source of income, but the poor guys does, for everyone rich person who is gambling has one or two businesses he or she is doing to survive from even if they lose big.
The thing that attracts people the most to gambling is their excessive greed. People say that they are having fun to cover up their greed to others, but in reality it is not fun. In fact, the origin of fun is human greed. Gamblers think that only now can they get 10X or 20X or 100X, from small to huge which cannot be found anywhere else or through any medium, that is why people actually say that they did it under the guise of fun. And this excessive greed turns them into gamblers at some point. Gambling addiction can be present in both the rich and the poor. However, I agree with one thing and that is that the rich can handle greed but the poor cannot, so they suffer more than the rich.