In Present Like A Pro, their book on professional public speaking, Cyndi Maxey and Kevin E. O'Connor suggest that teachers sometimes let their expertise stand in the way of good teaching:
Too often when we present we think of ourselves as experts. We are experts, of course, but we should not believe our own advertising. That wrongheaded approach often befalls other experts; it’s an attitude that says, “The audience should come to me.” We then rely on lecture as the only means of communicating.
In the scientific community, for example, this is widespread, accepted, and unfortunate. Often, we have heard scientists come out of a meeting lauding the expert for her knowledge, but shaking their heads out of boredom or frustration. Experts tend to rely on superior knowledge. Many experts are teachers with superior knowledge. They just aren’t master teachers. (227-228)