Why was Charles Dickens so manichean?

Esther Summerson is perfect. She has no faults. She is pure good. Every adult who treats of her is flawed, bad, evil, a fool, or in one instance only, John Jarndyce, unrealistically selfless. I'm having trouble getting through the first "Esther's Narrative" in my replacement copy of Bleak House. There never was an Esther Summerson. There may not have been an Addie Pray either, but she is WAY more believable as a character than any child in Dickens oeuvre.