We aren't going to get rid of guns. The 2nd Amendment isn't going anywhere and gun ownership is very high here. We have regulated legal firearms every way we can. I doubt that we will ever really even attempt to get rid of gun ownership in the US. We should increase the penalties for illegal gun ownership dramatically as one step.
Then we can ask ourselves why so many shootings occur in schools. I think a major reason is that there are no armed guards or police allowed at the schools. Go to a school with a loaded gun, and you're the only armed person there. You are able to shoot at teachers and children until either an unarmed person risks their life to stop you, or someone with a gun arrives to stop you. The latter happened in this case, after 21 people were shot, 19 fatally.
As for societal acceptance of the dangers of gun ownership- many of us drive cars, even though we know that hundreds of thousands of people die every year in auto accidents, with millions more injured, some seriously. We drive anyway. We also keep working to make cars safer and drivers smarter and more responsible. We could eliminate auto deaths by getting rid of cars, but we have come to accept a death toll far higher than that from guns because we cannot see our way to doing that.
There are no perfect solutions. If you can get rid of guns, get rid of them and enjoy a safer society. If you can't, keep working to make society safer in other ways. Trying to score political points every time someone massacres a bunch of innocent people doesn't make anyone safer.