General AI

What is the point of having a General AI instead of highly-tuned(optimized) specialized software fit for the task?
I.e. the "human-like AI" vs domain-specific software

>>6 What i'm hinting at, is that we will eventually create survival-centric human-like AI with all human flaws(egoism, greed, manipulative behavior, distrust, rationalization of own deeds, etc) and all the emotional baggage(emotions play important role in cognition: http://scholarpedia.org/article/Cognition_and_emotion , reward/inhibition networks in the brain, pleasure-seeking/pain-avoidance etc).