There's no reason that exploration games require resource management related systems akin to earlier editions of D&D. In fact, those systems were some of the most awkward bits of earlier edition computer games.
In Never Winter Nights, for example, your daily resources included all of the usual 3e daily spells and abilities, plus hit points. What did this accomplish? Well, it created a time tax on the player. Right before every major fight you had to press the "Rest" key, and sit and wait while a bar filled. That was it. It contributed nothing else to the game. Your abilities were ALL functionally per encounter, except that you had to waste some time to make them work correctly.
In comparison, look at a game like the Avernum series, an old school series of adventure games made by a small studio. They're probably some of the highest quality adventure games out there, if you leave out graphics. Each one has an incredibly rich plotline (ok, one of them doesn't, but of the 6, 5 have rich plotlines). And their combat is completely, 100% tactical and grid based. Each episode of the game uses slightly different rules as the designers refine their system and their techniques, but its a perfect example of a small studio getting things mostly right with a tactical rpg with heavy elements of exploration.
So what makes exploration such a key theme in Avernum?
Plot design. Plot design and nothing but plot design.
In Avernum 5, which I've recently played, here's a rough spoiler free summary of the first 1/10 or so of the plot.
You start out in a town. You adventure outwards, and reach another town. The areas away from the road are dangerous to you, and you may die if you go there. You are given quests, which require you to foray into these dangerous areas. At first, you need to stay carefully on track with your quests, because the danger elsewhere is too great. Eventually, as you complete quests and gain skill, you can start to control your own destiny, and you learn that the area you are in is quite vast, and filled with all kinds of weird hazards. After you've mastered the region you're in, you venture further into the depths of this world, and come to a coastal town. Here you receive a boat, which opens up all kinds of new options for you. Most of these new options are too dangerous for you, but if you're careful and stick to the water and the one island with a friendly town that you'll find as you explore, you'll be ok until you learn to handle this region of the game. Etc.
That's right. Its points of light.
Its all about the plot. Not the resource management technique or the combat style.