What did he mean when he said this well reasoned opinion?

“When a young male (let’s say 14 to 19) is a danger to himself and others, society gives the supporting family two options: 1. Watch people die. 2. Kill your own son. Those are your only options. I chose #1 and watched my stepson die. I was relieved he took no one else with him.”

“If you think there is a third choice, in which your wisdom and tough love, along with government services, ‘fixes’ that broken young man, you are living in a delusion. There are no other options. You have to either murder your own son or watch him die and maybe kill others.”

That’s surely from the calm rational mind of someone not filled with resentment and hate right?

It's certainly not filled with hate or resentment. Scott spoke at length about his stepson's death and it was always with sadness and regret.

Some context? What exactly happened with his son, and I assume he elaborated on what those two options mean, or what specifically they were in his case?