I don't see the fun in this. I'm happy they left it out. Unnecessary micromanagement.
It's not that it's fun or not. It's that the game is based on a ruleset that has been designed and tested based on certain things, everything balanced to that end. When you change something like this (regen time), you may unbalance some things, remove the need for some spells/skills, which in turn makes it so you have too many skill points to distribute, so you either reduce these, or let characters be much more powerful than they should. It's like a domino effect. Besides, camping to recover mana/health can actually add to the game in the form of ambushes, random encounters, some inter-character interactions, etc.