Still haven't seen any rigorous scientific evidence that child-to-adult spread is a major risk (at least not at the middle school and younger levels). We know that adult-to-adult spread certainly is a risk, so adults should stay masked and stay away from one another within the school building. I don't think these problems are impossible to overcome.
I'm not saying you're wrong here, but I'm going to highlight the important phrasing.
When we're dealing with the sheer volume of 50 million students and 3.5 million teachers, even a minor or infinitesimal risk still yields dead kids and dead teachers.
I'm not going to say a teacher's life is worth more than any other profession's, but I will point out the reasonable expectation of choosing certain careers is different. A person going into medicine/nursing/EMT work knows they're going to be exposed to this sort of thing, or at least the reasonable possibility of it. Police officers know, going in, that their job will be more dangerous than average, dealing with criminals and guns and such.
Teachers never signed up for all the school shootings that happened, despite probably nearly 100% of them willing to take a bullet for their students. We didn't choose this profession thinking we'd be thrown into buildings full of contagious people (exaggeration, I know) against our will. But that's not even it - much like the sacrificial attitude in an active shooter situation, teachers are, by and large, an extremely empathetic population. It's not even about us, it's about the small % of young deaths that will become inevitable. It's about kids bringing the virus home and their parents or grandparents dying.
We simply don't want to be a part of that. And we've got normal-citizen-filled school boards making these decisions, influenced by (in some places) no-mask-for-me communities. Hell, an Orange Co., CA school board voted to start back school with no masks or preventative measures. It's insanity. They're guaranteeing SOME child deaths, teacher deaths, and family deaths. Dead people who wouldn't be dead, otherwise.