Well, apparently; people still hate him for leaving his family, even when he did have valid reasons, even when he was completely unappreciated by the rest of the Weasleys, and he realized his mistake, he made up with them, calling himself a fool in the process {which, considering his pride, is a pretty big thing} and getting to be happy for all of two seconds.
I just.
Don't know how can someone hate him?
He's precious.