I think weaponry can be modern and vegan. I'm learning a few nunchuku katas in my martial art and it's great. They are doing wonders for my dexderity, hand-eye coordination and more stuff I'm sure that I'm not even aware of.
They don't have to be used to bash people's brains in, either. Most of what I know is defensive blocking and parrying (sp?), especially against knives which I think are used at least as frequently now as ever (well, at least where I live). Granted I don't walk around caring my weapons with me (okay, I sort of do because I keep them in my gym bag and I alway have that with me!), but other common objects can be used similarly.
Also, I think it keeps the tradition alive so weaponry doesn't become a lost art form. My husband is learning bokken techniques in Aikido, and that is one of the most passive and no-harm-philosophy martial art that I know of!
But that is just what I think. Thanks for reading