Opinion piece (by me):
I believe some drivers are ignorant or in willful denial about their driving skills or their ability to drive a car safely at any given moment. I think this is mostly because it's difficult to give up the freedom & independence that comes with driving. My grandmother and great aunt come to mind. All the church ladies were dependent on Gram for rides to Sunday services, so it wasn't just her loss when she had to give it up. It was her friends who couldn't drive, too. She was from a generation where husbands drove, so some of the women she picked up were widows who'd never driven a day. And my great aunt had to get in a handful of accidents, mostly fender benders, but one very serious, before she got the hint.
Until we fall back, it is dark when I leave my house in the a.m. Though I'm certain there are no buses between me and work at that time, it's why I leave my house when I do, I still use caution. Bus routes & pickup times can change, but not only that. There are other flashing lights out there to be mindful of. Last Thursday, I ran into three sets of flashing lights during my morning commute. Had I not heeded them, even though I wasn't certain at first what they were due to darkness, I still slowed down. If I had used the same reasoning as AS, I would have hit a tree in the road, clipped a delivery driver getting into his vehicle, and/or hit a garbage truck. And this was on a route I was familiar with! So, it wasn't solely about being mindful of a school bus, but all flashing lights, not just for the safety of others, but my own as well.
But, through all this, something seems to have been overlooked: AS actions also put her passengers in danger. Had it been a garbage truck backing into the trailer park to empty a dumpster that she didn't recognize, this would have had a whole different ending. So, it wasn't solely about not recognizing the school bus. It's also about her decision not to drive defensively on behalf of herself and her own children & sibling that is also disturbing.