It's nothing new under the sun for you to find someone who was having no money, suddenly comes in contact with some good amount of money, and next thing they start acting rudely and arrogantly. It's as though the money got into their head as it's usually said. They now feel invulnerable and invincible, and take other people as lesser species.
The reason why some people become very rude and lose every sense of humility is because they start to estimate their importance so highly. Pride gets into their head. Well, you know the popular saying - pride goes before a fall. This kind of behavior is mostly seen in people who come from a humble background. People who had nothing, and suddenly became very rich. It's occasionally seen in some people from privileged background.
Such a behavior repels people so much. Remember that everybody wants to feel loved and respected. But when you start making people feel so low and making yourself seem very superior, what happens is that - silently, so many people will be wishing for your downfall. They'll be hoping that things go bad for you. Whereas it shouldn't be like that.
Not that I'm suggesting that you should go around licking people's boots, but there's a way you should treat people with more respect and regard. We are all constantly struggling to become richer and better financially. And when that finally happens, we shouldn't just throw away our respect for other people into the wind. We should stay humble and modest.
I've personally found that the rich people, who stay humble, keep on growing richer, for reasons unbeknown. The humble rich person becomes more likable, having more good relationships, and gets more businesses going smoothly, as everyone feels happy and loved and respected doing business with them. They don't put anyone down, as a result they keep on going higher.