I'm sorry you seem to have met some of the worst. Thomas Stanley, author of "The Millionaire Next Door," "Secrets of the Millionaire Mind," and "Stop Acting Rich," has done a lot of research on them since I think the mid-70's. He found that the greatest concentration of millionaires are plumbers that own their own business, buy used Ford Taurus's, and shop at Target. So, I'm just saying that you probably meet a lot of people everyday that you wouldn't guess are millionaires.
I think that money just gives a person more freedom to show who they really are. Those who are greedy and arrogant will flaunt it more and generous people will give more. I love what Bill Gates and Warren Buffet are doing. They've convinced a group of 40 billionaires (and counting) to give at least half of their net worth to charities of their choice.
I agree that many millionaires are mean and unhappy. But, I think more are generally happy, kind, and quietly generous - trying to avoid recognition for their giving. I hope you get to meet more of those.