It's a valid point. Another valid point is at that time it was known the FDA had a history of approving addictive drugs. It is not evidence based to trust FDA over hundreds of years of history countering otherwise. I knew LOTS of people who turned down or tossed opiate scripts during that time because the long history was obvious to anyone with half a brain.
Yep, many people knew all along. Many didn't know, but doctors of all people had no excuse to be among the not knowers.