Because government is always a fight about resources. More resources in the hands of common people and to make their lives better is less money in the hands of powerful corporations and individuals, be it in the form of higher taxes for the rich or less direct money going to their enterprises.
One of the big issues is money in politics. Our congresspeople make a killing off of legal insider trading, they take huge donations from companies, and the supreme court has even said that it's cool to give "gratuities" in exchange for legislation or court rulings you like.
Corruption is killing this country.