This seems to flagrantly ignore the parents' need to be to work on time. I think the kids will ultimately be the ones suffering because the parents will struggle that much more. No, the bus is not always an option, nor is leaving your kid alone at home for any amount of time.
This bill applies to middle and high school kids. If you can't leave your high schooler home alone for any amount of time then you probably have bigger problems to deal with than school start time.