The issue is that some people see the world in terms of goodies and baddies. Not just in the USA either, people on STW do it too.
There are indeed goodies and baddies, but there are people in between, and people who move between the two. Most pro gun arguments run along the lines of “If the good people have guns, they can shoot the bad people and save the good people”.
Which is patently obviously flawed to anyone over the age of 12 of course, but there is a complication. The guns are ALREADY out there. Stopping sales of new guns won’t get rid of what’s already there. The horse has already bolted.
That’s a problem to which no-one really has an answer, imo.