The roads are already built, and the towns are already laid out in ways that require cars. Arguing that the roads, towns, and cars could be changed so that walking to school is reasonable... while technically true, is not particularly useful in anything but the very long term. There isn't the money to do that.

So yes, because of the way the roads, towns, and cars exist today, it is not reasonable to have kids walk to school in many cases. The weather conditions for the area are one of the things that go into that calculation; they are one of the obstacles that add up to it not being realistic. Are they the root cause? No. But it's irrelevant, because they _are_ one of the factors involved in outcome. If the weather was always perfect, then those children could walk to school year round. If dedicated walking paths were created that cars could not travel on were created, then those children could walk to school year round. Neither one of those is going to happen.

> It's not the snow that is dangerous, it's the cars.

Pretending it's realistic to magic all the car focused town layouts away is completely and utterly unrealistic, so I'd ask you to not pretend that "if we just admitted cars were the problem, all the problems would go away".