Typically in stories where ai is outlawed, it's written that way so that it makes sense that people are controlling anything at all (instead of just letting the computer handle it).
There's lots of stories of non-anthropomorphic intelligences that are human friendly. Sometimes humans do bad things with them, but they're not evil. "Shall we play a game?", HAL9000, Phaecian ships of antiquity, or those of the Culture. Androids seem uniquely unfortunate, perhaps as another poster noted, because of the stories of golem.
I find the paperclip optimizer a very useful parable.
The machine isn't evil. It doesn't want to do anything wrong. It doesn't hate humans. It doesn't need to have any particular shapes or design details in the stories. All it needs to have is a singular goal, capabilities, and a disregard for anything else in the universe to be a civilization ending cataclysm.
