From Guild Wars Wiki
An old folk legend states the only reason Dolyaks were domesticated instead of minotaurs is because minotaurs would rather be beaten to death than obey a command. Dolyaks, simply put, were less stubborn. Minotaurs are one of the oldest species in Tyria and are very much prized by the Norn for their warm, furry coats. They were once extremely populous throughout the Shiverpeaks but now reside solely in the northern regions, where they have sheltered valleys and caves to make their homes.
–Guild Wars Eye of the North Manuscript