Is it only the character of Khmer people?

it is a story said about the character of the khmer people in PhnomPenh related to the "Money is Power". you every morning i used to go to have breakfast in one restaurant where there are so many people like to have it there because of the quality of the food. i used to park my car near to the restaurant and always, there is one guide who use to guide me to park when i'm going to park and getting out from the park. most of the time i used to give some tip to him with around 500-1000 riels. you know during a few day i did not give him a tip because i don't have a small money and then when i go agian to park the guide who used to help me to park don't help me again and he stay in calm. I don't know why?$$$$$$$$$$$$$$$$$$$$

another story is the same in my working place. security guide will not want to take care us to help us for car parking if we don't give some tip for them. therefore i think that money is power and i don't know whether it is a good character or not. it is happen only in Cambodia or everywhere in the world. i think maybe it is the same for other country. i know that they need some sort of money but they should not think that car driver have a small money everyday giving tip them. ok! i know that the salary for them is so little bt they should act properly.