Well, first off, it's called the Bill of Rights, not the "Bill of Needs." I find your false premise that I have to justify my God-given human rights to you or anyone, so repugnant it's laughable. But, just for grins, I'll give you an answer.
Borepatch reminds us that today is the 21st anniversary of the 1992 LA riots, where the authorities basically abandoned the city to rampaging mobs of urban savages. These mobs, due to a hundred years of Proglodyte race-baiting and enforced dependence, were composed of ignorant racists who harbor a deep, bitter resentment towards anyone who works hard and succeeds. So they descended on LA's Koreatown--composed of hardworking, successful Americans--with the intent of destroying it.
That didn't work out too well.
According to the Los Angeles Times, “From the rooftops of their supermarkets, a group of Koreans armed with shotguns and automatic weapons peered onto the smoky streets…Koreans have turned their pastel-colored mini-malls into fortresses against looters tide.”When the cops crap their pants and run away, leaving you facing a horde of barbarians, it's a bit too late to run down to the local gun shop and stock up. In the end, you are the only one responsible for your own defense. If you wish to put your trust in the empty promises of the government, that's your ill-considered decision. But the evidence of history is not on your side.
Rhee claimed that the storeowners shot off 500 rounds into the sky and ground in order to break up the masses of people. The only weapons able to clear that much ammo in a very short time are assault weapons. Single shot pistols or rifles might not have been able to deter the crowd hell-bent on destroying the neighborhood.
By the end of the day storeowners had slain four looters and fended off the mob. It would be 24 more hours until the National Guard arrived and another two days before the riots were completely put down. Had the riots occurred just a couple of years later when the Congress banned assault weapons, many of these storeowners may not have been so lucky. It’s situations like the LA riots, which, while being rare, can occur anywhere from the streets of Los Angeles to far off countries during the Arab Spring.
So, that's one big reason why Americans "need" firepower: to protect themselves from the consequences of Proglodyte policies. Any questions?