Well technically you could explore this alone with enough eggs however you make a completely valid point. The issue for me is that as you said, you can go pretty much anywhere in the game solo. Comparing this to full team activities- solo players already have far much more to do. Therefore I think any new land should have at least, in some parts, massive amounts of aggro that need a full team to get around. I still enjoy trekking around different regions solo but am always disappointed by the lack of team activities there is to do.