There really is a problem with US society - it’s not only that there are too many guns (there are) - but even if you compare with countries where there are guns around (like SA) the number of massacres is just nuts. The fact that those in power don’t want to do something about it - I’ll never be able to understand those people.
It seems to be something to do with a combination of a 'cowboy mentality' and a 'grievance mentality'.
The 'cowboy' part says that every 'good man' is fiercely independent and constantly under threat, and is both expected and entitled to use violence to deal with 'bad men'. Part of this is linked to race, but is mostly (it seems to me) about the 'pioneering individual'. This combination of 'pioneer virtue' and fearfulness, creates 'be armed' and 'shoot first' mentalities that results in routine gun violence, as in the case of people being shot in minor confrontations. This seems very peculiar to the USA, and I suspect it is a consequence of its history as, supposedly, an untamed land colonised by arriviste adventurers.
Then you have a 'grievance mentality', where some people (notably depressed adolescents and angry old geezers) want to both be noticed and have 'revenge' on a society that they feel has ill-treated them. This is pretty common the world over, not just a US thing, and in most countries results in things like vandalism, football hooliganism and voting for demagogues.
If you combine the grievance element with the almost uniquely American cowboy element, and then add guns, you get both daily 'routine' shootings and pretty frequent mass shootings.