I think that could be explained easily. I don't like worlds which turn around the "hero" and his/her group and I don't like companions which are 100% to the main heros taste and licking his/her ... all the time. As allegedly the world is big and wild, there could be space for more parties of heros traveling around. The companions you see in the camp during rests do their own business the day over, they are just too polite to inform you how boring your adventures are in comparison to their own.