if people here were allowed guns then i'm pretty sure that most of my village would end up dead LoL
This is a very common misconception that leads people to beg their fellow citizens be disarmed. They haven't killed you with cars, power tools, or kitchen knives, have they?
While this thread isn't about firearms, I think firearms are the perfect example for why most people don't train with unorthadox weapons. The larger or more complicated a weapon is to use, the less likely you will have it with you or be able to effectively employ it in self defense. Nunchuka require training to not hit yourself while using them. A 7-foot long weapon with a 4-foot handle and 3-foot blade might be an effective weapon, but it's not practical for carry or even for home defense inside most home settings.
Compare those with a firearm. Firearms are designed to be user friendly, and are just as deadly no matter whether you have a kid, someone with a couple hours of range time, or a Navy SEAL shooting them (although the SEAL might be more deadly with it). It requires safety precautions so you don't hurt yourself or cause collateral damage, but it is a lot easier to use than most common weapons, let alone unorthadox.
I don't think it's bad to learn something unique, but I think most people who do weapons training do so for coordination (i.e. nunchucka or staves), sport, or self defense, and for pretty much all of those there are reasons why the common weapons are common.