People that critique capitalism tend to do it a lot because it drives a substantial portion of human activity right now. Capitalism is probably the primary driver of all violence in the US so it seems relevant. Under a socialist system, there could be lower levels of isolation and inequality, no incentive for gun companies to increase profits so they wouldn't market their guns to every person in America, etc. The defense industry is massive and tied directly to the issue of mass shooters. And when you say 'fix the household,' what does that mean other than dismantle capitalism?