I don't think you need repression. How about this simple explanation:

Everybody knowns that machines have no emotions and thus the AI starts off this way. However, after a while totally emotionless characters become really boring...

Ok, time for the writer to give the AI some emotions! Good AIs feel happiness and fall in love (awww... so sweet), and bad AIs get angry and mad (grrrr... kick butt!).

Good guys win, bad guys loose... and the audience leaves happy with the story.

I think it's as simple as that. Reality? Ha! Screw reality.

(If it's not obvious from the above, I almost never like science fiction. I think the original 3 Star wars, Terminator 2, 2001: A space odyssey, and Mary Shelly's Frankenstein are the only works of science fiction I've ever really liked. I've pretty much given up on the genre.)