I marveled at a friend's ability to teach reading. Her extraordinary approach inspired me more when I thought about the fact that this friend didn't learn to read until she was in her twenties. How can an individual who was such a late bloomer in reading, teach reading well?
The truth is that in many ways it's much easier to teach subjects that were challenging for you to learn than subjects that were easy for you to learn. For example, I never had too much trouble when it came to reading comprehension. While I wasn't necessarily an early reader mostly due to environmental issues, I didn't struggle with reading like some. That has made it a bit more difficult for me to teach reading as it is more difficult for me to break it down and understand the steps that children have trouble with. On the other hand, in areas that I've struggled with, areas where I've had to read a lot and practice a lot to understand, I find it much easier to teach since the learning of those topics was so memorable to me, and the struggle unforgettable.
This is similar to the recovering alcoholic who becomes the best coach and teacher to those trying to deal with their addictions. That alcoholic has been there, they know how those desiring to rid themselves of the cruel addition feel and what they can do to alleviate the curse that alcoholism is. The best teachers of any topic or subject are often the ones that had to work the hardest to learn the skill or trade--they know what it is like to be an eager learner in that arena and they understand the challenges, set-backs, and little wins that occur along the way.
So be careful before you judge a teacher's words or effort. Instead listen to their story and understand why it is they've chosen to teach a particular skill, task, or topic in a particular way. Sometimes their past struggle is their greatest teaching strength.