The Supreme Court is to blame
No one is pointing to the real problem. The blood of innocents is on the hands of supreme court justices who voted in favor of individual right vs. collective rights for gun ownership as outlined in the second amendment. The SCOTUS decision strengthened the gun lobby funded organization NRA which made everyone believe that gun ownership for the purpose of recreation and hunting is somehow a constitutional right. This has led to a significant weakening of gun control laws and dumb arguments like "guns don't kill people, people kill people", "cars also kill people so ban them", "bad guys will always get guns", "knives can also kill people" and so on. As a party, Republicans are to blame because they advocate for lax gun control laws.
The gun lobbyists blame gun violence on mental illness, a myth, which has been proven wrong by experts in field of mental health. No such connection exists.