Your explanation above makes me think that this is the way children must think in bad home situations (and you must have acquired this way of thinking in childhood). Children need their parents to take care of them so they need to see them as capable. If their parent is flawed who will take care of them properly. What a great explanation you have just provided.

I have heard it explained that people blame themselves because this gives them some power. They feel safer if they caused the problems because they have control over themselves. If someone else caused the problems they can't control that.