The following was posted as a comment on The Economist website to an article on demonizing bankers in the January 7, 2012 issue.
The reason bankers are the focus of economic frustrations is that they create money when they make loans.
By creating money they have lots of opportunities to take cuts for themselves, they have the power to say what projects go ahead and by whom and they get to charge rent (interest) on the money they create. Those are three good reasons for people to hate them and for bankers to tolerate the hatred.
(The author of this comment has a web log on economics at https://economics102.wordpress.com/)