I loved the open access of Baldur's Gate. I still remember my first time going into Thalantyr's little magic keep outside Beregost and thinking, "Oh, he's got some good items here! I will have to come back later when I have some money." And Beregost itself always felt like coming home, with lots of background noise and chatter, several townsfolk going about their business, etc. It was always a good place to rest and sell off some items. Every house in Beregost had a door and then something inside, unlike the lonely streets of Neverwinter. Certain quests required returning to the town, even very late in the game ... why waste resources on a new setting for every single quest?. Open access to key areas gives a sense of belonging and permanence to the fantasy setting, and I think we humans all feel that kind of connection to a place once in a while ... it's good to come back to familiarity after long outings in the Underdark, sewers, and pocket planes. To quote Pink Floyd, "When I come home, cold and tired, it's good to warm my bones beside the fire."
I think that the Camp serves that function even if its mobile, you can talk to Camp Followers, Mercanaries, and Companions at the Camp, buy things (eventually), events occur at the camp, ect...
