re: Are a person's "issues" a direct result of their parents?

No way it is just parents.

A lot of it is wiring.

My parents raised my brother and I the same. They gave us just enough to be successful and made us work for the extras. We were taught about Jesus but given the freedom to handle religion how we wanted. Not sure how that fits in here but it sounded good.
Now I am no where near perfect. I have my problems. Drugs and I were great friends when I was younger. However, one day I figured it out and am doing pretty well for myself. I am on my 7th year in education and about to purchase my second rental property.

Brother on the other hand is a lazy dog. Constantly needing more of this and more of that. Blames all his problems on everyone and refuses to fix himself. He is 25, graduated high school at 17 and can't seem to get through college. Delivers pizza, is an alcoholic and won't talk to anyone in the family unless he needs something. It sad.

Is this a perfect answer? No but I used to think it was all nurture. However, after living it, wiring is huge in this discussion.