Performance on none winter compound tyres drops off around 7-8 degrees C so I base my choice to go the winter route on that basis, rather than marketing.
But then the winters don't work well above those temperatures. Temperatures across all winter months span the ranges of winter vs non-winter tyres, that's why I'd prefer an all season tyre and not have to worry about it. The marketing comment was down to the fact that I didn't even know winter tyres existed a few years ago and now they are a "must". If we lived in St Petersburg I'd be right up for it, plus studs, but we don't.