Certainly a well thought out article and I do agree with a lot of it. Still, as someone who grew up in the 50's, I have a different opinion on physical punishment than you do. My father was known to spank on occasion and I think he was right to do so.
Yes, teaching about consequences for actions is important, but the physical aspect of that is way over simplified. What needs to be conveyed is that "hitting in anger" is wrong and no one should ever strike a child in anger, ever. Still, in rare and measured circumstances, a little physical intervention can be useful and beneficial.
Many years ago, there was a situation where a girlfriend was visiting with her kids. The little boy started eyeing a glass figurine on a table and started reaching for it. I told him "No" and that he would get his hand slapped if he grabbed for it. He did and I did. Then I put my arms around him and told him that I loved him and didn't ever want to have to hurt him. I told him that he knew what would happen and that he had to understand that, if I told him something, I meant it. All in all, he ended up knowing he could trust that I would live up to whatever I said to him, promises as well as consequences. That even extended to his sister who had just been an observer. She had a moment right after this that she glanced at the figurine just to test me. I just looked at her and told her, "don't, you know what will happen". She took a look at me and went to do something else.
Kids need consequences that are unpleasant enough to be deterrents. They need to understand that you love them and that any consequences are directly related to what they did and not your angry reaction to what they did. Whatever you do, they need to see it as being fair and part of your job to teach them about rules and consequences.
If a child understands rules and consequences, as well as that the consequence will be quite unpleasant, they will behave in a way that makes punishment rarely needed. When you give a child a 'punishment' that they think 'isn't all that bad', they may decide that they want the "forbidden thing" more than they don't want the "punishment". It may seem like a good trade-off. It's a complicated situation that's a little bit different for every parent-child situation.