Of course it has nothing to do with Anakin. In HP's world, Anakin is prolly a character no Magic-user even knows of, maybe even to Harry and Hermione, who were in school when TPM came out. The comparison was used to explain the kind of reasoning that JKR might have used in subjecting Harry to all she did. In RL, sadly, insanely abusive conditions can persist for years/decades, but you are correct in that Harry's living conditions would called down the police eventually--in RL. Dumbledore would never actually say 'It Toughened You Up' - to him it was a dice roll in a desperate situation, and it speaks to the darker, more complete view of him we later see. JKR would never have DD say all that, because an author must needs put their characters through situations that chill the soul. There can be no real justification for the Dursleys, only a literary one. The Harry we saw chose to gain from this admittedly obscene hardship, and not let it make him another kind of monster or enervate him. Look to another version of your own avatar--taking a 'should never have happened' situation and using it to actually move up in the ranks of the DCU power-brokers. That the Dursley situation was absurd is a given, and McGoncall could have easily called them the worst sort of people, period, and not been too far off. They were a neccesary evil, the sand in the oyster's shell, if you will.
