The straps and hip belt wetting through suck. Especially when they freeze. I hate bringing packs in the tent, as we've gotten older and a comftorable sleeping arrangement helps the hike. I just try to stay dry and clean as possible because its comftorable to me. What's in my pack usually varies by season and region.
Maybe it'd be better to not worry about it, but the small amount of care it takes makes sense to me.