All things being equal, I'd say that Cavil is the one who needs defending the most. He was right. Building meat robots that can't transmigrate into metal bodies at will is kind of absurd. From a design standpoint, the Final Five were completely wrong. It would have been much more efficient to produce a resurrection system that could drop a personality into any body it wants, including artificial ones. Also, the Colonies probably deserved to be nuked, because they were all giant assholes.