Even if bullying ended (virtually impossible because that's almost a default human behavior in society) there would still be mass shootings because most of the mass shootings had nothing to do with bullying in the first place.

But all this is beside the point of my original question.

Btw, why won't America instill strong regulations on guns anyways (ie, background checks)?

You keep going on with the argument that guns are not to blame but the people that use them are. That's true. But the argument has no strength further than stating the obvious. Guns are not to blame but they have a potential for great danger. And you can't "fix" humans down to an individual level. That's just virtually impossible. Some people are just crazy and it only takes one to do great damage. That's why Americans need regulations on guns. Guns you can control. Humans you can't.