I agree. This article espouses the exact management approach my wife and I take with our son, 7, and daughter, 5. I find that it works in both theory and practice.
In practice it works just fine at home when I am helping my son and daughter manage their own behaviors.
Where I teach though, as a middle school teacher in a class of 30-34 students, I'm afraid that this management system works only in theory. I agree with you that I can take time out to reason, when I have time, with students that are having difficulty. I practice a reasoned approach whenever possible. When I do this, management of the larger group can get very messy. My attention can be focused on one particular student out of 30 or so, for a limited time before ther rest of the group goes wayward.