Diplomacy, not technology
A quote from Gruber, via Norvig in 2009, on the sociology of developing ontologies:
In some domains, competing factions each want to promote their own ontology. In other domains, the entrenched leaders of the field oppose any ontology because it would level the playing field for their competitors. This is a problem in diplomacy, not technology. As Tom Gruber says, “Every ontology is a treaty—a social agreement—among people with some common motive in sharing.”13 When a motive for sharing is lacking, so are common ontologies.
13. "Interview of Tom Gruber," AIS SIGSEMIS Bull., vol. 1, no. 3, 2004.
Reminds me of the WWW2006 panel on tagging vs the Semantic Web, where I acknowledged that symbolic methods are no match for statistical methods when it comes to natural language processing and a lot of other tasks, I don't want computation of my bank balance crowd-sourced.
Medicine has a long tradition of controlled vocabularies, but they originate from billing systems. I suppose they have a role in evidence-based medicine, but that role isn't entirely clear to me yet. I'm pretty new to the field.