I'm not seeing any evidence of the other half of the US society not accepting school shootings.
If people truly cared about it, you'd go out on the street and protest, and waging a general strike in school and related areas until something is being done about it.
Instead 99% of the population seems complacent, and do mostly nothing about it, everyone (mostly) is still sending their kids to schools, teachers are still going to work and everything is business as usual.