In my opinion, FOO issues explain coping mechanisms we develop, why we put up walls, our boundaries, self esteem, morals and beliefs, what we value, etc....they shape who we become as an adult. They are not to blame for the As, so much as creating the pathway and shaping the person that allows them to happen. My H has FOO issues, as do I, but he chose to have As not me...his FOO issues may have led him down a path of self hatred, depression and lack of boundaries/entitled personality, but it was his choice to have As, even if these things made him vulnerable.
I think examining FOO will help you learn to grow as a person and break away from old childhood coping mechanisms that are no longer needed as an adult, but I don't believe they will give a 'reason' for the As. Some part of the why, sure, it's all part of the 'big picture, but it's not the only reason/blame for the choices of an adult IMO...if FOO issues were the only reason for the As, then every child of an alcoholic would become an alcoholic...and that's just not how it works, albeit they are predisposed with genetics and environmental factors...there are still choices to be made as an adult.
The best way I can think to explain it would be my own example. I developed a coping mechanism as a child to put up walls when someone hurts me badly. Those walls kept me safe in an environment/situation that as a child I had no way out of...it's not like I could just leave when someone hurt me. As an adult, I have choices. I can communicate on the level of mutual respecting adults, or I can leave...I didn't have these options as a child...I had nowhere to go, so the walls kept my vulnerable self 'safe' and protected from my parents issues. As an adult I no longer need to put up these walls when someone hurts me...I have options, and I can use other coping mechanisms that I wasn't mature enough to deal with back then (IC, meditation, processing the information from an adult perspective, etc). This is a FOO issue I have, and so I have to learn new ways to deal with being hurt...ways that I will actually heal instead of blocking out people and emotions that hurt me.
I think learning about FOO issues can help both the BS and the WS, I just get leery when it gets used as a way to explain the As. Plenty of people grew up in worse situations than my H and yet choose to live their lives in positive ways.