I think it's slightly weird that any time people are killed with a gun, a certain portion of the population decides that we now need to ban guns.
When a nice young family is splattered around a telephone pole, nobody calls for a ban on cars. The logic with guns is that it wouldn't have happened without it, so we need to ban it. Yet the car crash wouldn't have happened either without the car, and we don't feel the need to ban motor vehicles.
1,900 people die on the roads each year in the UK, and I don't think this includes pedestrians hit by cars. I'd imagine the number of children killed in the UK alone this year either while on the road, or from being hit as pedestrians is >20.
The only difference I can see is that a lot of people are anti-gun and inevitably blame it for the death, whereas most people have a car and view any car death as a simple tragedy.
Even when the gun is clearly not at fault, a lot of people still feel the need to blame it. For example, when that NFL linebacker shot his girlfriend - he used a gun, so clearly this wouldn't have happened without a gun, right? This ignores the fact that he's a very large, trained, professional athlete who would have no problem killing me, let alone a small woman.
Even when someone is murdered with a knife, nobody again blames the availability of a knife. When someone goes on a killing spree with a knife or an axe and kills ten people in China, it's a footnote in the paper. When someone goes on a killing spree with a gun, it's sensationalized and is always front page news.
I think there might be a number of things at play here, which you're not taking into account. Firstly, you have to consider the fact that few people call for outright bans on firearms after such a shooting, and most people don't take such calls seriously. What is far more common is a call to increase regulation of firearms or restrict access to particular types of weapons that are perceived as more dangerous (often this is itself based on ignorance about firearms, but that's another issue entirely).
This sort of response is far from unique to firearms. In the 1980s the MADD movement reacted to high levels of drunk driving by calling on stricter regulation of drunk drivers.
Serious air accidents result in calls to increase regulation of air safety. Terrorist incidents result in calls to increase national security and counter-terrorism measures.
In New Zealand high numbers of drownings in backyard pools resulted in laws regulating such things as fencing. High numbers of brain injury from cycling accidents resulted in mandatory use of helmets. Currently there are calls to restrict the engine size of cars for young drivers because of the problems with so-called "boy racers".
There is nothing really unusual about the way society reacts to killing sprees with guns.
But when comparing killing sprees to other causes of death and injury, it's very important not to make direct comparisons, because there are numerous factors that affect how people react to them. Such as:
1. Frequency - you have to take into account how widespread the event is to assess the level of danger. Americans make billions of car trips every single years, so while the death and injury rate is quite high, relative to the volume of car use it's actually rather low.
2. Severity - you'll note that one-off shootings or single suicides seldom result in calls to restrict guns, despite representing the lion's share of gun violence. High-casualty events always cause more calls for restrictions. If we were seeing single car accidents resulting in enormous numbers of injury and death you'd see widespread calls to increase regulation of cars too (which is why society regulates air travel far, far more tightly than motor vehicle travel). To use a car example, there are periodic calls to impose speed limits on German autobahns, and these often follow particularly spectacular car accidents which result from very high speeds. In September 2011 a school bus in New Zealand collided with a logging truck, resulting in over 30 children being injured, and this led to widespread calls to put seat belts on school buses and prohibit standing passengers.
3. Benefit-Cost Relationship - ultimately any sort of control comes down to society's perceived benefit-cost balance. The more useful and important something is seen to be, the more harm society is willing to accept. Guns are not as vital to society as motor cars, therefore society will generally not accept as high a cost for retaining use of them. Once you get into specific
types of firearm, the perceived usefulness of those items can often decrease even further. For example you'll often hear people remark that they don't mind people having guns, but they shouldn't have "assault weapons" as they're not necessary. Likewise countries like Australia, the UK and New Zealand apply greater restriction to weapons that are perceived as unnecessary.
4. Perceived effectiveness of increased control - this comes back to the misguided calls to ban "assault weapons" that you hear about. When people are ignorant of an issue they might seek changes because they think they'll make a difference. Something that is already highly regulated is less likely to be made safer by more regulation. Many people view firearms as poorly regulated, so there's an assumption that tighter regulation will make them safer.