I'm taken aback by the lack of compassion for the mentally ill. I hope I'm misreading the responses here, but I almost get the impression of a sense of glee that the mentally ill "got what they had coming".
Just because someone is mentally ill does not mean they have a low IQ or are an "idiot". It doesn't mean they are using their mental illness as an "excuse". It's not like they chose to be mentally ill; I'm sure these folks would much prefer not to have to deal with their mental illness.
As for "sick and tired", well, that's just rhetoric designed to appeal to the emotion. If I say I'm "sick and tired" of hearing people pile on the mentally ill, does that leave you any more convinced of my position? No? Ok, then we're even.
I'm not saying that we give the mentally ill a free pass just because they have a mental illness. Obviously, we have to do what we have to do to protect the safety of passengers. That's only natural. But I'm saying that just because someone has a mental illness doesn't make them an inconsiderate evildoer. I'd prefer to do what we have to do to protect ourselves, but to temper it with a little bit of compassion for those who struggle with mental illness and to recognize that the actions needed to protect ourselves may be necessary but nonetheless regrettable.
Let's resist the temptation to turn this into some kind of morality play where the mentally ill are the bad guys. Life isn't that simple.