I’m so sick of schools closing because of a light dusting of snow. Do they not understand parents still have to work?

I would need your definition of a 'light dusting of snow'. The sensationalist media will 'teacher-bash' with such phraseology (or other 'lazy' groups they decide to target). If snow is rare, which it increasingly is where I live, there is no point in the local authorities spending my local taxes on storing snow clearing equipment for three years and then bringing it out for one day. If it truly is only a light dusting and that is true for the entire region, there is no reason to close the schools or anything else. However, if the reputable forecast is for heavy snow and the advice is not to travel only the most irresponsible authority will demand that teachers and children make the trip to school. Forecasts can be wrong and I've been on the receiving end of that when the 'wrong' call was made and a perfectly safe day of schooling was cancelled.

In countries where snow is a regular occurrence, everything is in place to enable most things to continue except in extreme circumstances. I can never remember my school being closed for snow, but it was a regular part of winter in the UK in those days. Not so now with the climate changing.