Why are some people so judgemental?

I know what you mean I know a person who had the same problem since he went to high school, because in her class there were mostly rich kids so she now has the complex of being poor although she is not actually poor but has less money than those rich kids had. So in order not to show that she had less money then they did she developed few habits like laying about her experiences and possesions, talking about trips that had never happened, giving more importance to the job of her parents than it was necessary...people today really like to mind other people+s business so I think that we all develope some kind of defence system to avoid the attack or even win in a fight. I stared university agan after I dropped out few years ago, and so many people asked my parents why do they pay for my university again when I had already dropped out once who says I wouldn't do it again. I hate these people, mind your own business I'd say to them but my mother doesn't want me to be rude to them. I had good talk with my parents before I went back to University and they said it was ok, now I really try my best to finish as soon as possible so who are these people to judge me? Are they the ones who give me the money, are they the ones who study?