Guess what, I did run metasploit (and more) on school network. Nobody died.
And the fact is, if more people started exploiting things, things would get fixed. It's not 2000 anymore when neither vendors nor users gave any fuck about security. Nowadays metasploit doesn't turn you into as much of a god as it used to :)
And "creating porn, bomb threats, cyberstalking" - come on, anybody who wants that, can do that without school-provided computers. And yet few people actually do.