^
I would simply say there is no penalty for mismanaging resources. In DA2, gold ultra-plentiful, potions were dropped constantly if you actually used them, loot equipment off of enemies (such as 3-Star Ring) was level scaled and usually infinitely better than named or bought equipment... DA2 offered zero way, in my book, to fail in terms of resources.
I, too, grew up on PnP and old-school RPGs. And OF COURSE you get into the habit to go back to camp to regain your Vancian spells and double up on your supplies. Because if you didn't, you would face certain death and failure. Yet that thrill of being low, but not being "tapped out" on healing or spells, trying to make it just a little further or bolting as fast as you could to the exit... those were tense moments.
And why else would I suggest something except for how it would make the gamer feel? This is a form of entertainment... how you feel when playing the game is the whole point. If you feel bored exploring because your party is automatically healed and is just prepared to take down a gaggle of mooks five hours into a dungeon as they are five minutes, then it loses all sense of thrill, all sense of urgency. That "okay, here's another fork in the road... guess I'll go left. Oh, this leads into a much larger chamber that is likely the "right way" to keep progressing through the dungeon, so let me double back and go the other way to see if there is any loot/chests... oh! Random mook fight. Rah-rah-rah... Okay, moth eaten scarf in the chest... <sigh>... okay, back to the other room..."
It makes everything tedious. As opposed to "crap, I've been getting pummeled in this dungeon. I'm a little shaky on health and my healer's mana is starting to scrap the bottom. Fork in the road... going left. Ooooh, big room... should I go back to see if there is a chest? It might be risky... but it might be a mana potion, too. Okay... AHHHHH! Giant spiders! Evasive manuevers! Evasive maneuvers! Opening chest... WTF?!!! A moth-eaten scarf?! Curse you, level designer! You shall rue the day!"
To me, the enjoyment of success is only as bitter as the chance for failure. If the only way to fail is to have one really bad fight (at which point, you can just reload to right before the fight, anyway) then it makes fights arbitrarily hard or tedious. This was a big complaint for boss fights - that they were just huge HP bloats. The reason for this, in my mind, is that the encounter designer went into it knowing you would be at maximum health and mana. Give the Arishok a one-hit-kill move, usable at any time? Sure, why not. It's not like the player is going to be winded after fighting through an entire city of Qunari soldiers or anything.
I'd say those people who find resource management tedious are victims of poor encounter design. You can fall into the habit of using the exact same expedition prep tactics for every dungeon (sleep outside, stock up on healing and mana potions, only use spells in case of emergency) just like a game can have you fall into the same tactics in battle. Both are bad and can be mitigated. For instance, sleeping right outside a cave might result in being attacked while sleeping at a higher rate than could be found in "safer" areas. You could have special enemies/encounters which tried to steal or destroy your potion reserves (think gremlins in Ultima or the gnome thieves in the Golden Axe games). Or a dungeon were the enemies are highly resistant to physical damage and need the offense of spell casting in much more prevalent fashion, reducing the ability to use magic healing as a crutch.
Point being... if you feel a mechanic is unnecessarily frustrating, getting rid of it may wind up taking too much of the challenge away, resulting in overall boredom and possibly even further problems down the line. I feel that this is what was done with the Auto-Regen functions in RPG games. Too little risk, too much hand-holding.