Excellent article, thank you. I would argue that while significance is most certainly a part of what these shooters are after, it goes beyond significance: they're looking for agency. A while back I listened to an incredibly insightful video connecting the dots on what's wrong with America - and the western world in general - and one of my takeaways is that an entire population being enslaved and oppressed by the very institutions that are supposed to be taking care of it is wiring up its individuals to self-destruct. If we study hard, and work hard, and still feel like life is futile while we struggle to make ends meet? Something's got to give.