Perhaps because as Americans we are all failing.  It is happening over and over again and we don't want to seem to come up with solutions.  Mental health programs are woefully short on public funding, politicians are afraid of passing any gun safety laws, and all we seem to do is argue back and forth and nothing ever gets done. Unfortunately I am not a lot of help since I don't know what the solution might be.  We can start with banning bump-stocks and not allowing those who are found guilty of domestic abuse crimes to own a gun.  We can fund mental health and drug treatment (instead of throwing users in jail).  In general we need to figure out how to work together.  My suggestions, for what it is worth.  A huge cultural change will take a generation but what is ultimately needed.