The very fundamental problem with this is that technology has allowed humans to magnify ability to get things done for ages. Humans have always used technology as tools to further their own goals and agendas. Scientists are designing these general intelligence AI not for their own means but for the means of corporate companies who wish to monopolize total control of intellectual facets of humanity as well as means of intellectual production. They will not exterminate humanity because humans will never give up control to another that would be an inherrent threat. Humans have defense mechanisms within them known as "self-preservation" which deters this. However it is far more probablistic that they will be used to enforce total dependency of the population and subvert what remaining power is left. Thus it could be more definied as a technological dictatorship designed to keep the masses in line.