I'm not speaking matter-of-factly here, but I'm pretty sure this is an early access thing. There's one area that I recall not being able to fast travel in, so I couldn't long rest. It would make sense to me to expand that to any place that isn't in the overworld, or even just more areas if nothing else.
I definitely agree with adding short rests, and restricting long rests more. Could even be a difficulty difference potentially.
