Y'all have provided rules-supported answers. However, I'm glad this is a game where I, as GM, can ignore the parts I don't like.
WotC is more about, "Kill and fight and loot because it's fun!" instead of "Why are we doing this, again?"
Ah, see that's the problem. You ignore the parts you don't like. Not just the rules, but what people tell you.
Here is a perfect example:
Stop ignoring the facts already presented to you.
See? That right there.
Okay, here's the truth. The undead don't exist. This entire argument is moot.
But we are dealing in hypotheticals. We have a shared and agreed upon paradigm. That paradigm is set down by WotC for d20 3.5. If you wish to discuss something else, you need to indicate that you are using a different paradigm. My statements are based on that shared group paradigm. My statements, within that framework, are fact.
littha thinks it's a joke.
That why we cannot see eye to eye. I, and everyone else who accepts that undead are evil, is using the same paradigm. You and littha have decided to ignore the d20 3.5 paradigm of objective morality. No matter how much you may want it to change, d20 is objective Morality. There is a section for varient rules involving Subjective morality, but that is not cannon.
If you wish to discuss subjective morality, that's fine. Start a new thread and state up front that you wish to argue the point using a completely different world few. I'd be happy to discuss it.
But I find it annoying when people just ignore facts because they think the facts can be interperted differently. There is no other way to see the rules under d20 3.5. Period. Sorry. Start a new thread asking about undead in a subjective universe, but stop trying to change the fundimental laws of dungeons and dragons.
The original question is: Why are Undead so Hated?
This question has been answered many times. You keep trying verbal gymnastics to try and convince people that undead arn't so bad. You have failed to convince me that I should like the undead, and I'm a damn open minded guy. If you can't convince ME, I seriously doubt you could convince more then oh... 1% of any given average nation in most D&D settings that undead aren't so bad.
If you can't convince me, you sure as hell can't convince a dirt farmer. And Thus, THAT is why undead are hated.