What Richelle Dunn is preaching might seem easy when you hear it, but it's not that simple in practice.
Firstly, parents are adults. They are accustomed to adult thinking, and often look at their children from a superior perspective. Therefore, to start seeing things from their kids' perspective requires a shift in their thinking, which is difficult enough in itself.
Secondly, refraining from imposing their will onto their children doesn't come naturally to many parents. Many parents have a tendency to control their children, viewing them as extensions of themselves. They want their kids to accomplish what they, themselves, couldn't. As such, it's challenging to resist coercing them.