Culture, religion, race, ethnicity, and soforth are all somewhat less significant societal dividers than that of labour. The plurality of time spent working in ones life creates a deep attachment to a profession, a trade, an art, or a craft much more than we often care to admit. Those who share professions most often are the best suited to understand the struggle and needs of those in the same industry, leaving it as a logical step to suggest that it is this organisational grouping of people that most makes sense.