The teachers want the paycheck and benefits, but they would prefer collecting it without dealing with the kids. Kind of like the US Forest Service admin people, been home drawing full pay for months and loving it. In the end teaching is just another government job (and one with not a stellar track record)
The parents with grammar school kids would like to see school start up to ease the financial burden of child care, and it's a big burden. Hired a babysitter lately?
All this has a lot more to do with money than health. Gotta wonder what the teachers unions are thinking now, if they play along politically with keeping it closed, at some point they are going to start losing buildings and grounds, taxpayers don't feel like funding empty buildings, private enterprise can teach via computer...maybe better, the unions will start losing people that pay for over extended retirement funds. Far reaching consequences and big sea changes ahead.
