It means they don't care enough to meaningfully make sacrifices for change. To deal with school shootings is to change the constitution. The American constitution is basically wired for school shootings. To change the constitution is basically a civil war.

Things aren't binary. Many people care deeply about school shootings. But they don't have the means or power to organize to stop them and, individually, they are powerless.

They’re not binary, but when an issue persists for decades, over the course of multiple administrations, and political landscape… it shows either the country is incompetent in terms of solving an issue, or the issue is not a priority.

I wholeheartedly believe US can solve issues when it’s an important one. And thus, I think, for an average American it’s not an issue.

Decades is a very long timeframe. Countries have achieved more in shorter periods.