To work on the David and Goliath analogy,
Killzone 2 is David, the Haters are Goliath.
Goliath loved David's older brother, but he became a druggie and a criminal. Goliath thought this would run in the family, and didn't think David could be any better, and so began to hate David. Over the years, Goliath gained power and many people fell prey to him. Despite the occasional good deed, most considered him a monster.
When some promise was shown, he dismissed it, said there was none. More was shown, still he refused to believe in David.
Then, people began to really like David, and this made Goliath furious. He began to attack David, abusing him verbally and physically.
However, David overcame all of this, with the strength of his fans behind him, and defeated Goliath.
Still a pretty good story.