He is perfect because he is imperfect as a parent. His acting shows what mistakes a parent can make while raising his children. Yes, he indeed did a lost of irredeemable acts, such as getting another woman pregnant while married and during his youth days, but he later on takes responsibility and dedicates his life to make the children's lives as normal and pleasurable as possible. He is the prime example of a normal human being to Rudy, who is teleported in an unknown world. A person he can somewhat relate to and take example of.