When things get real bad here in the Midwest snowmobilers help out.
The Pa Turnpike is a limited access road (toll road). The entry points are toll plazas, in some cases 30’plus miles apart. There are very few emergency access points...and if you look at the Mass photos, the roadbed is surrounded by hilly terrain and roadway lined by guardrail of jersey barriers. Not snow mobile friendly at all. People don’t understand how mountainous Pa is.
Except for fire trails through the mountains, “open country” in PA is not passable as it is in the Midwest. I could probably go completely unobstructed from KC to Minneapolis, or Chicago to Fort Collins on a snowmobile. Can’t do that here. Once you’re into the mountains, the ridges go endlessly from Southwest to Northeast. Trying to go (largely) due east or west (as the turnpike does), or due north or south is not realistic for any serious distance.
The terrain around the area is too steep for effective snowmobile operations, and in some areas you would have to traverse long distances to get to the PA Turnpike from nearby towns.
Also, unlike a lot of other interstates the PA Turnpike still has a lot of two lane sections, so once it gets jammed up it is harder to clear it and get traffic moving again.