So long as there is no agreed basis for the training and education of singers, there can be little or no faith in it. So, we have isolated teachers, a lack of coordination between departments, and poor outcomes generally. Everybody suffers, from the pupil, who is surely the focus of our attention, to the profession that we represent, to the audience for whom we all labour.
I remember somebody pointing out that you can always learn something from a teacher, however bad he or she might be! It is also the case that however good we think we are, we cannot know it all. We need the work of others to complement our own work, we need the knowledge and experience of others to fill in the gaps in our own, we are dependent on others to help us on our way. Conversely, if we do know a lot, or have something special to offer, we can help others and, by extension, the general cause, by sharing it.
Harrison, Peter T. Singing: Personal and performance values in training. Dunedin Academic Press Ltd.