maybe sometimes physical therapy should be the prescription for back pain

Part of the issue is they want people to get back to work in a typically short sighted fashion. Real treatment requires time where you cannot really work most jobs, where you do go through the slow process of physical therapy, and requires a social safety net that'll provide for you while it goes on. But if you load them up on pain killers and they can go back to work for awhile, before addiction takes too much of a toll.