Clearly, the folks running Hero Prep are as shortsighted as the ones in charge of Mad Scientist High. Instead of having some vaguely ill-tempered machines running around the football field, they might’ve gotten us rumbling down the path to our eventual destruction. We don’t want killer robots learning from Nietzsche, Machiavelli, Einstein, and the rest of the great thinkers that the kids at Herman Kahn Memorial High School study, do we? Not unless we want a Terminator/Matrix-style future to come to pass!
See, with an exception or two, the students at Mad Scientist High are interested primarily in ruling the world, not destroying it. If all your fellow humans are dead, then, sure, you might be the unquestioned lord and master of all you survey, but you won’t have anyone over whom to lord your newly acquired position. Since world domination is essentially an egomaniacal exercise, killing everybody doesn’t really allow you to succeed in your goal.
If you’re a killer robot, though, your path is pretty well set in front of you, and the only things that’ll limit your ability to achieve are the resources you have available. Since Hero Prep wasn’t willing to face off against the killer robots of Mad Scientist High again, and didn’t have the wherewithall to try to get them straight-up banned, now they’re just going to have more dangerous opponents in the future. How like “heroes,” huh?