Was above the tree line in Rocky Mountain National Park last week, and it started to sleet. On my Harley, BTW. And that road doesn't have a lot of guard rails. The traffic really started to slow down, to about 15 mph. It was actually work to keep the heavily loaded Harley balanced at those speeds.
Yes, the little cars causing all the slow down were afraid of the sleet and falling off the side of the road, and slowly drove past several pullouts. And yes, that was rude of them on one level.
But rather than gripe about it, or unfairly pick on one brand of car manufacturer, I just used a pull out myself and let them get ahead. Easy solution. Try it.