Would it be insensitive to suggest that the world would have been much better off if this guy had followed his own advice?

Even better would have been for authorities to have followed what in retrospect seems like a tremendously obvious path to the realization that Cho Seung-Hui wasn’t just a risk to commit suicide, but to hurt others. He belonged in a mental hospital and it’s a damned shame that he wasn’t sent where he so obviously belonged.

State police, meanwhile, revealed that in December 2005, Cho was declared “mentally ill and in need of hospitalization” and posed “an imminent danger,” according to a temporary detention order issued by a Virginia district court.
[...]
The disclosures about Cho’s past run-ins with authorities added to the rapidly growing list of warning signs that appeared well before 23-year-old student Cho went on his rampage. Among other things, Cho’s twisted, violence-filled writings and sullen, vacant-eyed demeanor had disturbed professors and students so much that he was removed from one English class and was repeatedly urged to get counseling.