https://www.psychologytoday.com/us/blog/checkpoints/202112/what-do-about-school-threats
Dr. Ferguson argues here for better mental health care and nuance rather than just throwing minors in prison for making threats.

"Obviously, the most worrying are those who seriously intend to carry out the threat.

Individuals who commit serious incidents of school violence may have chronic mental health problems, come from difficult homes, have a history of anger problems, and see themselves as victimized by others.

These are just general findings—not a definitive “profile.” Just as many people who fit this pattern never commit acts of violence, it’s important not to dismiss a threat because someone doesn’t fit this profile."
He has a point. He wants to prioritize mental health care and a supportive environment rather than just locking people up.

I question the point on mental hospitals (which isn't intended for the majority of cases).

They trend towards being prisons by another name and with far fewer processes for due process and human rights. With a prison, there is a process, and someone serves x amount of time, and then, they're out.

Also, we tend not to pretend that it isn't a situation where someone has a lot of power over others, and that can commonly be abused / misused.

It sounds really easy to say "just fix this", but it never really is that easy, as these tend to be very fundamental issues.