While I do think that Card presents abuse as horrific, I think he also portrays it as necessary. Even aside from Enders Game where it's the only way to save the world, abuse is shown in other books such as Hart's Hope and Songmaster as necessary to the moral development of the hero. Abuse may cause the hero to lose qualities he had as a child, but that's a necessary sacrifice to resolve the crisis, and in the process become a man.