I agree. Therefore winter tyres for most of UK is a bit of overkill. I would not be sure about Highlands as I have never been there in winter, but from what I was told even Aberdeen is getting rather wintry in summer.
The reason I changed them because they were getting low on tread. I try not to drive with bold tyres.
I lived in Aberdeen for many years, and didn't feel the need for winter tyres. OK there are a few days per year where there's snow on the roads, and tailbacks during rush hour, but nothing too bad weatherwise.
However, when I moved to Aberdeenshire 15 years ago, things are a little bit different. Some of the rural roads may not see a gritter/snow plough for a few days after the initial fall, and some of the side streets are pretty much left to the residents to clear themselves. At the time, I had a spare set of wheels with worn out track day tyres so took the opportunity to try a set of winter tyres. Transformed the car in low temps/frosty mornings even without snow, as the car just felt so much more planted on the roads, even at low speeds. The nervousness on bumpy wet roads had gone and when the snow and ice did arrive, the difference in traction and braking were hard to believe. I've fitted winter tyres to both our cars every year since. A small price to pay for increased levels of safety, even if it means I can move out of the way of another car about to have an accident (like failing to stop at a downhill junction coming ontp the main road I'm on).
In recent years, tyre technology has moved on a lot, and all season tyres have pretty much closed the gap to winter tyre for the typical winter conditions we get, and don't turn to jelly above 10C on dry roads. Even newer summer tyre designs are much better than they used to be in colder temperatures, as long as they have decent tread depth.