I understand what you want to say and have to say I'd prefer such a system over the current one as well but I think that'd require a huge rewrite of large parts of the game.
I did not say that it would be easy. But I think it is necessary.
Also we currently don't have enough areas available to do this. What do we do with areas that aren't implemented yet? ... black holes seem kinda out of place 
I know 2 possible ways of solving these problems:
1. If PS uses Hightmaps the developers could generate random hightmaps of the hole world.
2. Create some kind of barrier:
- a wall
- big mountains the players can not climb up
- ocean and after a mile the players can not swim any further
- forests the players can not walk through.
- lava
- some kind of magic barrier
- a deep chasm, the player die if they fall down