It doesn't. Every gun death has a human element to it.
Yes, every gun death also has a 'presence of a gun' element to it.
The difference generally speaking is that gun safety advocates understand this full well and make no attempt to refute it. 2A advocates meanwhile often argue implicitly or explicitly that the presence of a gun is not the issue, that instead is all about the people involved.
The fact that you can always find a person to blame (the parents in this example) is irrelevant to the fact that without a gun in the picture no child would have ended up dead. So when people say "guns don't kill people" that statement is just plain wrong in any meaningful sense.
The two elements (the person and the gun) will always be present in every gun death. The 2A advocate strategy is to pretend only one is to blame and then argue that one should be the person and not the gun (because how do you blame an object?). That's just childish simpleton nonsense. We need to look at the whole picture.
The other issue with blaming the parents is that there was no malice involved here, just irresponsibility. But human beings are inherently irresponsible, so while the criticism is valid in any individual scenario, it is not a valid argument when we're debating public policy. The argument there is essentially that human beings need to stop being human beings.
That is a good argument in favor of requiring those courses. I will be on board with this if the process is quick enough for someone who urgently needs a gun.
If someone urgently needs a gun that is all the more reason to not sell it to them. That's literally the point of a mandatory waiting period.
Not very high up, but that is irrelevant. Surely you could save some lives by passing lighter control, no?
Everything we do is a result of a cost/benefit analysis. Guns are a contentious issue because they are a frequent cause of unnecessary deaths in this country, while the benefits of having so many guns out there and so easily accessible is minimal.
Lighters are far more useful and necessary to the functioning of our society and cause no where near as many casualties. The idea that we would put all of these requirements in for lighters is therefore every bit as absurd as it sounds.