Only rich people can gamble for fun but most people gamble to make money. Besides gambling requires money so it is foolish to have fun with it. There are difficult and easy moments in gambling but there you should analyze with experience. In gambling you will always lose it is really false advertising so you have to collect money between losing and winning.
It's good that you said "MOST" rather than all because I'm one of the people out there that isn't gambling for money, but gambling for fun only. Take note that I'm not rich, and the term "RICH" is very broad, and subjective, but to cut it short, I'm not as rich as those famous businessmen out there and in fact, you might be richer than me.

Anyway, I agree with you that most of the average gamblers out there are gambling because they want more money. Though some are spending just a few bucks just to have some excitement while watching sports games, some are spending too much money because they want to make more money. You always lose in gambling? Most might be, but I believe that there are some gamblers out there (mostly those experienced ones) who are coming out with a huge amount of money.
To simplify it, if you're rich, you can gamble for fun. If you're poor, it will be hard for you to have a mindset where you will just gamble for fun. If you're an average person, you can choose between the two. Either you gamble for money, or gamble for fun. For me, I gamble mostly for fun, and money is just an addition to it.
