I don't see why it would be acceptable in one instance, but not in the other. It seems like a double standard to me. — Tzeentch
Because a society is not the same as a family. I grew up in a family where confrontations were rare. We seven children behaved ourselves without violence. Threats of violence? As my father would say, "If you don't stop complaining [crying, whining, etc], I'll give you something to complain about." Or, "If you don't stop squabbling [in the back seat], you can get out and walk home."
When were these threats turned into violence? They were not. Our parents' anger was novel enough for us to take it seriously all by itself. Were we ever spanked? Yes. Was that violence? No; it didn't rise to the level of violence. There are families where parents exercise violence freely; fists, kicks, hard slaps, belts, etc. I have seen this in action in families (and worse, actually) and I definitely do not approve of it.
There is no parent in society. There are citizens, and there is a government. there are written and unwritten rules governing interaction between citizens, and between the government and citizens. A lot of these rules have the force of law. There are penalties laid out for violating the law. Unwritten rules have penalties which result, too. Like, leave angry drunks alone. Threaten an angry drunk and you will likely get socked.
Societies have an implied social contracts which bind citizens to treating each other more or less civilly (and most of the time, the contract is honored). There are mutual obligations which are understood. The law, however, is not an IMPLIED social contract -- it is explicit. We understand that if we violate the law, there may well be quite unpleasant consequences. Prison is one of the possible consequences.
If you think being in prison is the same as being tortured, then that is what you think. I don't agree; I would vastly prefer not to be in prison, but it isn't ipso facto the same as torture. (That said, a prison certainly can be operated in such a way that it is torture).
I will agree that the threat of violence (of some material sort) lies behind governmental authority and power. Law and the social contract assigns to the state the privilege of exercising violence to compel compliance in designated situations. I'm OK with that. If we don't want to be the recipient of privileged violence, then we don't flagrantly violate the law. We are careful about when, where, how, and why we tempt the state into pouncing on us.
The smart rat doesn't tempt the cat to pounce, unless he's very near his bolt hole.