Earlier quoted context omitted.
I mean, yes, the thing that ultimately underpins all authority is the ability to exert physical force to see it honored. I'm not clear on what you're suggesting.
I think it's pretty clear that the parent is accusing the state of using torture to coerce compliance, which is a strong indication that the state itself is no longer legitimate.
Of course the state uses violence to extract compliance with social norms. That's what it's for. The much more interesting questions are about which norms it should enforce (criminal codes) using how much force (sentencing, prison conditions, police rules of engagement, etc) and subject to what controls (due process, civil rights, etc).