I have. To you. Repeatedly.
Primary reasons:
- Individuals can farm a given mob to generate more chances at a piece of loot.
- Resources respawn faster and can be farmed by individuals.
- Entering a cave means fighting your way in, AND fighting your way out.
- Respawns on top of someone drinking within the 30 second mark are far more painful.
It comes down to the fact that layers exclude players from all the other copies (once exploits are fixed) such that they can’t farm given mobs faster.