When considering the house edge and how the casino is making a profit for both themselves and the investors you need to realize gambling is not to make money but to have fun. That is why I have been gambling for YEARS now and never been disappointed because I have a limit that I put to myself and never break that which means I have fun but never feel sad when I lose.
Are you sure that you are gambling only for the purpose of having fun, because actually the people gambling here have a lot to make money. Well maybe you can say to the public that you are aiming for fun, but your heart is different, that is for money. If it's just for fun in a gambling game, why do we have to bet with risk can't we play without money and have fun?
Most people do most of these types of activities for fun. Stanford noted that about 92% of gamblers are mostly just in it for harmless/casual fun:
https://www.gsb.stanford.edu/insights/most-gamblers-are-just-out-funOf course, that leaves the remaining 8% that probably take it too far. You can say this type of thing about virtually any human activity, like alcohol. Most probably use it just fine, a few do not. Even healthy activities like exercise have people that take it too far and probably end up doing more damage to their bodies than good at the extreme end of the spectrum. A healthy balance for any of these activities is mostly for fun for most people and where the vast majority of the population will tend to end up.
As for why people have to bet money, that depends on the person, but the fantasy of winning a lot of money very quickly is more alluring to many than not. Many people that buy lottery tickets like the fantasy of what they would do if they win, even if they know it is unlikely. If gambling for fun for you or others is good enough, it's for that very reason that we have Federal Reserve Dollars (play money) on MintDice while most Bitcoin casinos do not offer such a service.
And naturally, we do not want problem gamblers on MintDice and we've added a few measures on our website for people to get help and we can block accounts as well through customer support.