It's simply not helpful to group them with the shootings that happen during school hours and target students/staff.
No, not really. Think about it: who is somehow trying to argue away school shootings based on arbitrary assertions? Do you think you can argue away the gun violence out of school grounds?
I would dare say that gun violence is bad all around, but here we are, trying to argue that some episodes should not count because of reasons. That would certainly reassure those attending those schools, as well as their family and communities.
Citation needed.
I assume your absolutist definition would only include incidents where a child made contact with and suffered harm from a fired bullet?
This data was compiled with the criteria it was to inflate the perceived number of "muh assault rifle" headliner-style school shootings. You're probably never going to turn on national news and see any reporting on any of these crime disputes that came to a head at/near a school. There is very little political willpower to do anything about these instances and not calling this shit out for what it is is a disservice to the people that are actually impacted by this strain of gun violence.
EDIT: after re-reading your comment a few more times, I think what you were trying to say is that it doesn't make sense that people would overlook some gun violence and worry more about other instances, but I've got bad news for you -- they do it all the fucking time. It's not that it's <people-they-don't-like>, it's <people-they-don't-think-about-at-all>, save when they make for a convenient data point.
Aren't you getting it entirely backwards, though? You're faced with a crisp definition of what a school shooting is, and you're somehow invested in arguing that a shooting taking place at a school isn't a school shooting because of your own arbitrary criteria.
Arguing whether a shooting should be considered a school shooting or not feels like you're completely missing the whole point that there are shootings taking place at schools, which I would imagine would be very concerning.
If you want my two cents: no shit gun violence is bad. It's just that that type of gun violence doesn't impact suburban whites, and it's incredibly disingenuous to have so much gnashing of teeth over the overall number when most people passionately talking about this only care about a certain subset of that number.
Those after-hours shootings-at-schools are part of a larger pattern of gun violence that advocates of gun control have basically never made a focus of.
It would have been rather disappointing to get hit by a stray bullet then, and know that it wasn’t considered as important as a daylight incident.