They will need to massacre the government if the government ever becomes *tyrannical,* as defined by them, and they need guns to massacre *bad guys,* as defined by them, in case the bad guys ever try to hurt other *people,* as defined by them, or even make those people *afraid,* as defined by them.
And it seems what they really want is the sole license to define these terms: person, bad guy, people, fear—and if you won't accept their definitions, that seems to be what the guns are for.