Why did the 11th Doctor hate the War Doctor?

Not only did the War Doctor join the Time War, he finished the Time War by detonating The Moment and wiping out both Daleks and Time Lords.

Or at least that's what he thought, after he regenerated into the Ninth, then Tenth, and Eleventh Doctors. He went for most of his next 3 regenerations actually believing he was guilty of genocide, which broke the promise he made to himself when he chose the name The Doctor.

From The Name of The Doctor Script:

DOCTOR: Look, my name, my real name, that is not the point. The name I chose is the Doctor. The name you choose, it's like, it's like a promise you make. He's the one who broke the promise.

WAR DOCTOR: What I did, I did without choice.

DOCTOR: I know.

WAR DOCTOR: In the name of peace and sanity.

DOCTOR: But not in the name of the Doctor.

From the Day of The Doctor script (I'm writing this from memory, as I've seen it more than 10 times. There could still be mistakes but the message is the same):

CLARA: You told me the name you chose was a promise. What was the promise?

TENTH DOCTOR: Never cruel or cowardly.

WAR DOCTOR: Never give up. Never give in.

Clearly, even though they're the same person, The Eleventh Doctor (and also the Tenth and probably the Ninth) had no choice but to hate the man they were before. We all have regrets, things we wish we could take back, and that was the reason. Only difference is The Doctor being a time traveling alien, actually had the chance to go back and undo his biggest regret.