The first news I saw of the Chicago teacher's strike was a headline on the Chicago Tribune that said, "I'm going to lose my job." It was not a quote from a teacher. It was a quote from a parent, who was worried about the time she was taking off from work because she had nowhere to send her kid.
This is not an isolated problem. The New York Post reported that Chicago schools and churches were opening doors during school hours so that kids were not left alone in homes. It's clear that the main function we lose when teachers strike is not learning, because it was already questionable how much learning goes on in Chicago public schools. The loss is childcare. School provides a safe place for kids to be while parents work.
It's also clear that public school serves as a safety net for the most at-risk kids. In the face of the strike, Chicago schools made an effort to continue to serve free breakfast and lunch to the kids who might not otherwise eat.
You are telling yourself that your school is not like this. But here's why your school is the same: Public school is a huge infrastructure set up as a social service program. It is terrible at teaching kids how to be successful adults, but it's great at providing a safe way to care for kids, no matter what their income level. (The blog Get Rich Slowly enthusiastically estimates that parents save $1000 a month by sending their kids to public school instead of paying for childcare.)
We see this clearly in the Chicago Tribune headline. But also it's clear when I tell people I homeschool. They say they could never be with their kids all day. School teaches that: schools teach parents learned incompetence that they are not able to be with their kids all day and they require a public babysitting service. But surely, this is not true for you. Or anyone, really.