I'm not sure what this comment means, sorry.

You run the heater to defrost the glass in your car. It often takes a few minutes for it to be effective. Otherwise, you can’t see and you’re a danger to yourself and others.

In the winter, it’s more common than putting gas in your car. It’s kinda odd explaining this though

I live in the subarctic region, a stone’s throw away from the arctic circle. We have snow and frost in winter.

We use ice scrapers. :) As a matter of self-reliance and/or common courtesy.

Defrosting the windows with the engine is really not nice, especially not when it’s a diesel with the fumes hanging in the winter air and going inside people’s windows and into baby carriages and kindergarteners’ noses.

It's not only not nice, it's a genuinely bad idea. If you have large sheets of glass (truck windows) and large heat differentials, you are asking for catastrophic failure due to uneven expansion. I know multiple people this has happened to personally, and there are also some truck manufacturers who recommend against this kind of defrosting for exactly this reason.