That quote is so totally non-scientific. For movies to get basic physics so terribly wrong is very sloppy.
Besides, the Matrix is about how our world is a simulation - who's to say how physics works in their "real" world?
NEO (politely): Excuse me, please.
MORPHEUS: Yes, Neo?
NEO: I've kept quiet for as long as I could, but I feel a certain need to speak up at this point. The human body is the most inefficient source of energy you could possibly imagine. The efficiency of a power plant at converting thermal energy into electricity decreases as you run the turbines at lower temperatures. If you had any sort of food humans could eat, it would be more efficient to burn it in a furnace than feed it to humans. And now you're telling me that their food is the bodies of the dead, fed to the living? Haven't you ever heard of the laws of thermodynamics?
MORPHEUS: Where did you hear about the laws of thermodynamics, Neo?
NEO: Anyone who's made it past one science class in high school ought to know about the laws of thermodynamics!
MORPHEUS: Where did you go to high school, Neo?
(Pause.)
NEO: ...in the Matrix.
MORPHEUS: The machines tell elegant lies.
(Pause.)
NEO (in a small voice): Could I please have a real physics textbook?
MORPHEUS: There is no such thing, Neo. The universe doesn't run on math.
The Technocore AIs of the book series were considerably more clever than the Matrix AIs, in that they were able to arrange their affairs such that the humans did not even realize the AI were using human brains as their processors. There was actually a human military objective to locate the Technocore's processing hardware, which I'm sure the AIs found amusing. Kwatz!