Re: your Chicago comparison, the terrain makes a difference imo.

I lived in Michigan for a few years and have driven around a lot in central Illinois, both of which I assume has a similar terrain as Chicago. Given a fixed amount of snow, I'm way more comfortable driving in Michigan or central Illinois than PA. Worse came to worse and I were to slide off a road, I'd likely just go into a field at a similar elevation as the road. If you slide off a road in PA, there's a chance you're dropping off of and into something. The hills themselves also make a difference in terms of impact on navigability. My SO who is from central Illinois is mildly terrified of driving around Pittsburgh in snow, so your friend isn't unique (not that it's entirely rational or justified).