Gurak uses his plantation as just a cover for his criminal operation of smuggling skooma. He has ties to both the Camonna Tong crime syndicate, and the Imperial Legion. Which allows him to run the operation without a hitch. He will attack the Nerevarine on sight, if detected in his home, or attempting to speak with him.
Though he has no direct connection to the quest, the Nerevarine must travel to his plantation to gather the ingredients.