It's not just guilt--it's a yen for control. Taking responsibility for the things that bad people do to us gives us the idea that somehow, we could have prevented our victimization.
In actuality, we have no control over our lives. People are mugged for no reason and stolen from at the least opportunity. Qualified, hard-working people can't get jobs or are fired out of hand. Madmen kill good people at random from university towers. We develop strange illnesses or conditions. We age when we don't want to.
So we, who are powerless, embrace the illusion of power and call it responsibility.