Sorry, but that study (and the one by Kellerman) have been pretty thoroughly debunked. If you want so good statistics, see the Kleck and Gertz study:
http://www.guncite.com/gun_control_gcdguse.html
Also, read the book More Guns Less Crime, by Professor John Lott.
Statistics aside, I have the moral right and duty to protect myself from unwarranted aggression. This right was recognized in the middle ages as existing independently of any government, and was codified in the English Bill of rights, which was one source of inspiration for our own Second Amendment. That a gun helps me in that effort is indisputable.