Very true - 400 mill guns - hard to get the them off the streets. But other countries have - Australia put severe restrictions on guns after 1 mass shooting. Everyone screamed and yelled, but just a few years later, the vast majority of the country was very happy.
My stance is this: Is the country better with lots of guns - or no guns. Why not work toward the best option. 1 step at a time.
You cant just give up because there are to many out there. But yes its a complex problem with no easy solution. But as a nation, we just sit back and accept it - and that is the sick part.