I occasionally spank my sons.
I try to use it as an absolute last resort and I always explain to them before and afterwards what they did wrong, what they should have done, and the occasional consequences of making bad choices.
You can talk and assign reprimands all day long, but occasionally something more punitive is needed in some situations.
I know some individuals that don't lay a hand on their child and that is their prerogative, but I work with children daily and I've seen very real world examples of what happens when you let certain behavior go unchecked or take a more lax and diplomatic approach to discipline.
Obviously, there are exceptions to every rule, but most of those parents have more lax parenting techniques as it comes down to disciplining and communicating expectations to their child.