I agree that blaming the past can stand in the way of overcoming it, but a step in overcoming is to sort out formative experiences and re-evaluate them. That can lead to at least a temporary orientation of outwardly-aimed blame, in the effort to assign resposibility around all the relevant parties and experiences (including one's own poor decisions), on the path toward boundaries and personal responsibility. To take responsibility for the whole shebang without that sorting out just reinforces the inability to think clearly and creatively about one's change process.

~S~