Re: it is rare for civilian US gun owners to use their weapons legally against criminals
That's not merely an unsupported assertion but an inherently unverifiable one. I don't currently own any firearms but I hangout with people who do and read some boards where they hangout. Most report at least one instance in which they defused a potentially dangerous situation by displaying their legally carrier weapon. Perps ran away, nobody was hurt, no reports were filed.
Your assumption about burglars is equally flawed. If someone has broken into my house I don't know if he broke in to steal or to kill. There should never be an imposition on me to determine which. I am not the one who has already broken at least one law.