I think that the idea behind the hub is a good one but the photo was in bad taste. When I saw it, it actually put me off reading the hub.
Most of the people commenting are Americans and Americans are very pro guns. The rest of the world takes a much more conservative view on the matter. Gun safety for children is important if you have guns freely accessible in your home, it is not really relevant if you don’t. That is not to say that children shouldn’t know what a gun is and that it is dangerous.
Personally I am anti guns, anti hunting and generally anti anything that takes away a life of any kind (that includes a chainsaw or an axe that is used to cut trees), so I prefer teach my child love, peace, unity and respect of all living things rather than gun safety. But that’s just me and I respect everyone’s opinion and their right to free choice.