It's usually because, since they don't get snow very often, it's not worth investing thousands of dollars in equipment and thus, they don't have any way of clearing it when it does happen. There are areas in the US (especially the south) that completely shut down for a bit of snow too because they just don't have any way of dealing with it.
Funnily enough, the UK can cope with floods up to 20cm without even hitting the news, in London at that, we'd never manage THAT in Germany, where we don't give a fuck about what brits call snow. I always preferred the UK version. Snow happens less.
I think it's because our country's weather is so miserable most of the time, anything resembling a real season causes them to freak out. It happens in the summer too whenever it gets above 20 degrees, you know
You guys lock up(like most of wester and southern europe) because you lack the balls we north and east europeans have .
Now in all seriousness It's about being used to it and preparation. And more fine technology something uses the more vulnerable it is, such as Iphone 3(i recall it was that) had an issue of not working when exposed to cold. But the very same aplies to very hot places with lots of sand too.
Thsi reminds me, "why in fantasy works the nothmen are described as hardier that others?" Because we f*ing are!