Trying to stop the creation of AI is impossible. Assuming a method exists to create artificial intelligence, it will eventually be discovered no matter how complex.
AI has already benefited mankind in several ways, from fraud and spam detection, to natural language processing and self-driving cars. None of which would exist without AI research.
Any AI that was able to recursively self-improve would quickly become superintelligent: at that point, any set of goals it had that were not explicitly those of humanity as a whole would result in catastrophe, as the AI would use resources necessary for human life or happiness to achieve its goals.
Artificial Intelligence is our best hope for exploring extra-terrestrial worlds, by sending autonomous research and development machines who can perform without human intervention (due to the limits of the speed of light)
Unless the problem of employment and providing necessities to everyone is solved first, AI has the potential to displace huge numbers of human workers who no longer have a means to support themselves.
Because it's buzzword and vaporware. Silicon valley companies are deceiving everyone that they're great because they're doing bleeding edge high-tech but all that we see is 80s style speech recognition and merging dog faces into photos
Dumb machines are already a threat to humanity. Rocket + GPS is a big threat, adding AI can help to identify it there is a valid target or the machine should retreat.
Unless provided, an AI will naturally be devoid of aggressive tendencies, as it will not be subject to the evolutionary selection pressures that caused the need for aggression to develop. Further, there will be no competition for resources with Humans, so an AI would likely pose no threat to humans.