You might not go around hitting people but kids who are spanked will hit other children, so someone's parenting might become another child's problem.
I was brought up in the 70s/80s and my parents never had to hit me. So it wasn't all families and perhaps my not getting hit is part of why I just can't imagine being that cross with my children that I would hit them. And they have pushed all of our buttons from time to time.
I can understand someone who has never had children to think that spanking would be fine, a simple short solution to stop the current and achieve future behaviour that the parent desires.
Can you understand an alternative viewpoint that a parent just wouldn't smack their child regardless of how much of a dick they were being?
Children are these tiny humans that might not be able to control their actions and emotions efficiently when they are little, but they look to their parents for guidance, protection and understanding. And love.
How I thought about it, was I would have to be extremely angry to hit one of our babies, and the mood I would have to be in would be exactly the wrong time to lash out.
Not hitting isn't the quicker or even easier way to discipline, it's not. I think you would be much more hesitant if you did have children of your own.