But who is asking for perfect characters from perfect writers? Continuing to use Superman as an example, the whole point of his escapist fantasy is being true to his convictions and doing the impossible. that doesnt mean he doesnt have layers or personal flaws, especially in interpersonal dynamics.
Maggins "Miracle Monday" novel is really good at this. Writers aren't perfect, and i wouldnt say they automatically suck if they cant do this, but it may mean they are just not suited for a particular character.