That is the problem with painting the martial arts with such a broad brush. Many styles have techniques specifically designed to deal with knife/gun/weapon atta

That is the problem with painting the martial arts with such a broad brush. Many styles have techniques specifically designed to deal with knife/gun/weapon attacks, and some styles are designed mostly around dealing with such things. A broken bottle is probably not as dangerous as you may think. A knife, you are probably going to get cut but your attacker will fair far worse. A gun becomes less useful the closer an attacker is, during something like a mugging, they are typically very close. But, even when learning how to deal with an attacker with a knife or gun, any decent instructor will tell you the best response is just to give them what they want and get out of there. It is the same as when engaging in just a fist fight, it is more a matter of 'is this worth it' or 'do I have a choice here' rather than 'can I take this guy'.