It's not because she's rich, it's because she's an ahole. Her little "eat like a poor person" organic guacamole did it for me. In fact, that's why normal people hate most rich people - not because they're rich, but because they're aholes. Because most rich people ARE aholes. They may not have started out as aholes, but turned into one when they got a little scratch.
Rich aholes like to gather at ritzy fundraisers and nosh on expensive treats to "raise awareness of poverty". They like to wear matching ribbons supporting some fad cause at awards shows where everyone is dressed in an outfit that costs more than most people make in a year. These people could sell one of their mansions and feed a thousand hungry children for life, yet they don't do it. Instead, they get paid to do PSAs for child hunger. What Gwyneth spends on manicures and massages every year could buy an awful lot of goods for poor people, but she doesn't do it. Instead she does commercials imploring *us* to give out of our $50k a year income.
So yeah, that's why everyone hates Gwyneth and every other entitled greedy tiresome self-absorbed Hollywood ahole.