The thing with auto-regen in a RPG is that it spoils the world's credibility, and discourages the player from exporting real-life solutions into the game. It isn't logical.
Most RPGs are fantastical, but there are some rules even with magic, which is usually a form of energy that is drawn from a parallel plane by mages, priests, and the like. It's supposed to be a strenuous and skill-demanding task, and this is why only a handful of individuals are capable of using it. It's also is why people would turn to clerics or druids for healing, and wizards for trinkets and enchantments.
Finding a place to rest so that mages and priests can concentrate, study and pray for their spell powers to return is very logically pleasing within game terms. It handles the subject with finesse and respect. After resting they are once again ready to exert their will and strength unto casting healing spells and the like.
For a mana system like in DA, one would at least expect mages to either rest or consume mana potions before they would be ready to cast further spells (which, metagame thinking, this has been designed as such for balance purposes). Auto-regeneration obliterates these rules, takes away importance from potions and healing items, pays the heavy toll of removing interesting chained encounters, and removes that sense of planning and time passing. It's merely there to propel the action ever forward and allow encounter design laziness, which are both in the Codex book cataloged under "very bad" last time I heard.
Last time I heard RPGs weren't shooters, and rather, imaginary worlds with predefined, coherent sets of rules where players would role play a variety of characters and explore what sort of pressure and effect their actions would cause unto such a world. Gameplay mechanics are bound to these laws. Without them, without that sense of expectation, there is no sustenance to a world's credibility, and thus the suspension is broken. It's why characters die of falls, it's why characters get tired after a while, and why you would expect NPCs to lie, bluff, and kill their way to victory. It's supposed to be a playground of the real world, with all of its pitfalls.
I've never heard of a human being auto-regenerating his/her bullet wounds, or auto-resurrecting for that matter. Not yet, at least.