There are ways to deal with being mugged that don't involve shooting. In fact, it would probably be fairly difficult to pull out a gun in that situation.
I'm not sure if it's laziness or people just underestimate self defense/martial arts. Using guns solely to protect yourself is a crutch, and a very risky one (mostly for other innocent people) at that.
Do you think a school shooter would be very successful if the classroom he entered had a teacher or student that could go all Sandy Cheeks kara-tay on his trifling butt the moment they walked in?
Disarm and overpower, not shoot down.