They're not actually full of hatred. Do you remember that douchebag in your class at school who kept saying ridiculously offensive things in order to make his point? (that may have been me, I apologise) This is the same thing.
Westboro Baptist Church adhere to the true word of the Bible, as they see it. From their point of view, the debauchery, sloth and vice that (thankfully) make up a large part of Western day-to-day living are evil and need to be punished - fortunately, God has already punished everyone! He's making America fight in ridiculous wars, losing its brave soldiers! He's punished sodomy and drug usage with AIDS! He's cleaning up Ny'orleans, the centre of such disgusting acts of wanton recklessness as MUSIC ITSELF, the dread sceptre of Beelzebub himself! (Nyarlothep - Ny'orleans - COINCIDENCE?)
And o wow.
None of you guys has noticed that these acts are CLEARLY a campaign of orchestrated vengeance against a world that has never been more Christian, rather than a series of random and unconnected calamities and disasters. Of COURSE they've gone out to protest!
They just want you to see the truth that's right in front of you...*sniff*
More seriously:
They're deeply sad and disconnected people, ruled over by their psychotic and unkind father. It's probably not too surprising that they believe everyone else is a sad, disconnected person, being punished by a psychotic and unkind god.
For the deeply affecting human side to these people, I recommend watching Louis Theroux's documentary about the WBC, I think it's called "America's Most Hated Family".