Well, even you said yourself, knives are a different story. I only went with sticks because I don't think I have it in myself to stab someone just to avoid a beating. If I felt there was real danger to my wife or sister or something like that, different story. As far as just some punk with a BJJ purple belt who feels the need to prove he can kick my ass...I expect I would take the ass kicking before I put a knife in someone.
Point is, grappling is an issue but it's not the ultimate issue by a long shot. We live in an incredibly safe world these days (contrary to popular opinion) and virtually nobody in the US or Canada is in any real danger of being arm barred unless they go looking for it.