It is very easy to kill someone with a gun.. It is also very easy to imagine how impersonal an experience it can be doing so.
If you have to use a knife to kill someone, you are going to have to get very close to them to do it. You're going to have to be very aware of what you're doing. With a gun.. not so much.
It's also much easier to defend oneself against a knife attack in many cases. E.g. pick up chair, hold in between you and knifey guy; not exactly a great situation, but he's going to have to spend significant time and effort on each and every victim he goes after, and slowing things down greatly will dramatically reduce the body count.
Knives are simply much slower and less efficient for the task, especially against forewarned opponents (e.g. most of the potential victims in many mass-killing situations, and potential defenders), and it's vastly more likely the attacker will be stopped quickly even if he manages to kill a few people.
Lets not muddy the waters here. You mean the gunman could've used a number of crossbows, knives and rocks to take down so many people in such a short span of time?
Guns themselves don't kill people, but they make it highly efficient. Guns are tools, they create or enhance capabilities and as such they can be judged based on the probable outcomes of their usage.
[Spoons] themselves don't [make people fat], but they make it highly efficient. [Spoons] are tools, they create or enhance capabilities and as such they can be judged based on the outcomes of their usage.
That's actually true. There is a wealth of research that shows that things like having larger spoons and larger bowls causes people to eat more and therefore get fatter.
Similarly, is taking a crazy person's gun away going to stop them trying to kill people? Probably not, but it'll be much harder for them to kill anyone.
So perhaps you'd like your neighbor to acquire a nuke or smallpox-based vaccine. Sure, he's a great guy and will never use these things, and besides, nukes have plenty of other purposes in a household. Their primary reason is totally not for killing people, so this is all good, right?
Let's not resort to reductio ad absurdum arguments, please. There's plenty of rationale arguments that you could have made instead. No one's suggesting that people should be allowed to keep nuclear bombs in their homes, and your metaphor is untenable.
I see you saw my comment before my "probable" edit :). The purpose of spoons are to feed. The probability of getting fat as a consequence of using a spoon is small. The purpose of guns is to make killing efficient.