I didn't provide any reasoning. I just stated my opinion.
I guess my reasoning is mainly that Sith Lords cannot be fat, since being fat and thus being physically out of shape is a major weakness, and a weak Sith would immediately be attacked (and likely killed) by other Sith.
I suppose I should add that I don't hate Baras in the sense that his personality pisses me off and I want to kill him. I hate him in the sense that I think the character is all wrong and he shouldn't exist in the first place.