A thing about religious (and other) people and the illusion of free will

[Angrboda]

Moral culpability and legality are pretty distinct things, right?  It's not inconceivable that a person burns down a building and is apprehended as having done something good or righteous or justified - a hero - but it's still arson.  Conversely, to find a course of action reprehensible and utterly unconscionable - but perfectly legal.  

The simple answer is that we prevent arsonists from lighting fires because they are arsonists.  Because those fires often turn out to be consequential.  Because we have a compelling interest in preventing arson.  I don't see how it would matter, to that, whether we believed that they were morally culpable or whether we believed they could help themselves.  We blame them for the fire because they started the fire.  We restrict their freedom so that they do not start more fires.

That seems to be a "we do it because we do it" kind of response. It doesn't really address the question of why we restrict people's liberty for some things rather than others. Smoking and drinking likely have as much consequence as an arson or two, yet we don't restrict people who practice those habits.