It is natural to fear a powerful source that may outperform humans. The fact that AI applications can be programmed to perform so many skills to a better level than many if not all humans, and much more speedily is overwhelming but the main fear comes from the fact that AI will never have feelings.
A robot can be programmes to act ethically according to some human code but it will not be able to make decisions outside this; it cannot act out of love, fear, hate or sympathy. This is the true position of something 'inhuman'.
It can act against humans if programmed to do so. On the other hand, robots, even when known to be so, have been found good companions for the lonely or mentally defective.