I just hate the argument of "well, you ban guns, we're still going to find ways to kill people." What you're saying is that a knife or a golf club is just as effective a weapon as a firearm, when, truly, they're not in the least bit the same.
Guns are so attractive as weapons because they're designed to do just that, and as a result they're quick, easier, and more effective. Suicides by firearm are preferred because its fairly instant and painless, compared with bleeding to death after slitting wrists or slowly suffocating from hanging. Murder by firearm is easier because it's a matter of point-and-shoot, not charging up to someone and trying to stab them where they can defend themselves or trying to set them on fire.
You take away the things which make murder and suicide easy and accessible, then you make some people rethink doing it in the first place. I can guarantee you, if I was going to kill myself, I wouldn't want to A) see it or B) feel it.