Am I the only one who steadfastly opposes this? It doesn't fit into the idea of the player as the fortress planner/manager at all, so I guess I really shouldn't worry about it being implemented. Every reason in favor of this seems to boil down to "I want to submit dwarves to arbitrary violence on demand," major exception being those rules which should be orders, not laws. Fort mode != god mode.
It depends... a lot of this is potential for abuse, but cultural norms are really just laws themselves... Take clothing for example:
Don't wear shorts in public: Strong culture in some places.
Must wear burkha: Strong culture in some places, law in others (by civ)
Mustn't wear saggy pants: Law by noble with the intent of punishing a subgroup.
Dwarves going outside must be wearing coats: Smart rule by a benevelent spirit of the fortress.
The question isn't 'should we allow players to put arbitrary laws on the books' but 'how do we allow players to nudge dwarves in the right direction'.
We already create a large number of silly laws. Dwarves don't go outside, dwarves collect refuse, etc, etc. I figure that eventually there's going to need to be a standard risk/reward structure at the dwarf level, and that culture, civ and site rules, noble mandates, and player wishes are all going to be calculated into this, preferably in a standardized way.
Some things the players are going to continue to need near god control in (don't go outside), even if that's eventually toned down (but my cat is trapped! I must save it!) Others, serve as good nudge with the severity determined by how much control we're allowed to have (third world villages enforcing tribal dress in it's citizenry in order to preserve tourist dollars).
In short, being able to say 'All dwarves will wear pink blouses or they will be hammered' is maybe a bit dumb, but there's good stuff in the framework that could add a lot to the game (and standardize a lot of motivational elements) if it's properly game-balanced.