I get all that. But if you're standing there and for some reason some idjit grabs for your gun. What does bjj teach you to do? Throw them on the ground and attempt a rear naked choke?
It depends on a million things 'what would you do'. BJJ isn't rigid like old martial arts. It's hard to make up scenarios, you need to try a class so you can FEEL how big of a skill gap I'm talking about.
But to humor you, someone reaches for your gun you could always do an arm drag, and throw a bomb of an overhand left behind that, or if the person is charging you while reaching and giving a ton of momentum when you get the arm drag they'll just throw themselves.
In general you would be taught to move off the line of attack, control the space, improve the position, get an attack, then finish the fight.