With the new changes to poison and cure code, I just wanted to resurrect this idea. I feel the way poisons are going, it is sad to restrict it to just piercing weapon type.
Similarly still feel it sucks to be restricted to weapon type with backstab.
Since the discussion here was solid, didn't want to start a new thread on the subject. (Hopefully people won't get too angry because of that)
So I was thinking about this, and take this with a grain of salt since I don't know the code, but...
I like the idea that each 'weapon skill' kind has a slightly different thing that those who specialize in it can take advantage of. I hope this isn't giving too much away but:
(a) piercing weapons - can get laced with poisons
(b) bludgeoning weapons - you can knock your opponent out
(c) slashing weapons - not sure (maybe they do more damage)
(d) chopping weapons - not sure (maybe they do more damage)
Hence, a character when training has to pick and choose and can't just be good at all of them (at least initially): you want to be the guy who knocks people out -- train bludgeoning; want to be the gal that poisons fuckers, pick piercing, etc.
Another thing to think about is that if everyone focuses on piercing (so they can poison), then those with chopping have a little advantage since everyone's defense will also be checked against piercing and not chopping.
Anyway, that's my thoughts on the gameplay reasoning behind keeping poisoning limited to just a single weapon type.