"Why does anyone 'need' an AR-15?"
The answer is really quite simple, but first let me ask, Why does anyone 'need' a new corvette? Why does anyone 'need' a 10,000 Sq Ft house? Why does anyone 'need' diamond earrings? Why does anyone 'need' a yacht? Why does anyone 'need' a $500.00 pair of shoes? And so on and so forth. The 'Why' game is never-ending.
The answer to all such questions lies in the fact that America isn't about 'need'. America is about 'want'. You want it. You work hard for it. You get to have it and enjoy it, America.