From a gameplay perspective, this is a mechanic that needs to be in game in some form or another. Things like resting at a campfire or getting a room at an Inn can still be added for roleplaying purposes or for healing as well. The more options the better.
I totally fully agree. However, there is only one thing to heal so far: Hit Points. no mana, no stamina, no "fatigue" level that would temporarily decrease some mental (well, actually, the only mental) attribute until you rest, for example...
Larian's call. It seems they want to focus more on the story telling rather than some "complex" features.