Its just a matter of where you want your player input focused. Do you want it on the grid or in the collective minds of the others at the table?
Yep.
Combat in D&D was originally designed to be abstract, in order to leave a lot of room for creativity and input from the player. This is not the same as choosing a pre-defined option from a menu of powers.
The system was flexible and simple to accomodate a whole range of possible actions, including "I attack" if the player only had a peripheral interest in combat.
I think you're oversimplifying the situation a tad.
In theory, yes, the system allowed for a lot of creativity from the players. Which is more to say, the system didn't specifically prohibit it, and if the players thought of it, and the GM ran with it, then you were good.
What you seem to be glossing over, or outright missing, though, is that a lot of people don't do well with "blue sky", do whatever you can think of, options. There's even a term for it - option paralysis. When the list of possibilities becomes too great, some (many people, perhaps even most) find it difficult to make a decision.
It is like writing poetry. Some people do well with "free verse". But many others will just stare at the page, unable to choose a structure out of nothing. Give them just a little structure to start with, though, and they're off!
In 1e combat, for the most part, "I attack" was the explicit option in the rules, especially if you weren't a primary spellcaster. Everything else was blue sky. Eventually, you learned your GM, and the other options they supported with the internal rules became clear, and you weren't working blue sky anymore.
As time went on, in D&D and other games, designers learned to use more explicit rules, I think because it led to less guesswork early on in one's time with the game. It is easier in general for new GMs and players to have a good deal more structure. It is all well and good for long-term players to have huge amounts of freedom - at this point, they've developed standards, and never have "blue sky" problems. But, a new person picking up a game - especially a new GM - has a long road to hoe, setting up their own internal rules, if they aren't given options.
Now, I happen to feel that 4e went a little too far down that particular road, but I can see why the general tendency to take that walk is there.
Later editions began to provide more and more rule support for combat, while at the same time, reducing exploration play into a series of die rolls.
For combat lovers this poses no problem, but exploration and socially focused players get thier favorite parts of play squeezed out.
They are left right into the same place they always were, the place that combat also used to be in - the place where the majority of the rules are internal. The explicit rule is "I bluff", and beyond that, you're in the "Blue Sky/whatever the GM supports" arena again. Look at exploration and social areas of today's game like you look at combat in older systems - loose, with a lot of room for player creativity!
The contrast, though, is a bit stunning, and I would prefer they even it out a bit, or at least point it out more - "We made the combat explicit and complex, to reduce the learning curve into the area of the game it seems most folks want most. But social skills and other areas can be a rich game too, but we've left it to your GM to come up with the guidelines there."
And, actually, in 4e they did give a framework that can make the exploration and social games rich - the skill challenge. Unfortunately, they presented it *horribly*. The idea, however, is generally sound - set some levels of difficulty, and let the players figure out how they might use their skills and abilities to meet it.
Not unlike old-school combat.
