i think it's probably the fact that alaska is a really rough environment, and cars are generally not fond of those.

Like i said the majority of that doesn't have people living in it, so it's literally only walkable because there is no infrastructure what so ever. It's just cabins in the middle of nowhere.

The coast line i think is walkable primarily due to the unique economy and residential housing structures. You're not going to move far from where the work is in a place like alaska, you don't exactly get that luxury, so you're automatically in a more walkable "economy"

i believe a significant portion of the alaskan economy is fishing. Farming to my knowledge basically doesn't happen at scale, oil is another significant portion, but then again, that probably requires vehicles, so.