I remember the days of 1st Ed, when I would GM a group of guys back then. The
main drive was the killing of dragons or any creatures that might possess a near massive amount of treasure.
Honestly...that made me a bit disguisted with that. And began to slowly move away from that. Over time with other campiagns. I turned around the gold hunting mindset to deeper character interaction with the world, NPCs, and to other players. (Giving players something more meaty to deal with)
Today...I am the point now, I no longer place the need for gold hunting or pillaging for XP, or 'murdering' of some creature(s) just for kicks. Just to get XP.
Yes...the trend of that, did shifted in later editions. There was a sign of maturity filtering in, in the later years.
But, not to knock 4E but it was impressed upon me. It was just set for fighting. I did not entertain the idea of going backwards again. After 2 decades of game changing and growth.
Back then...even video games carried that mindset of killing monsters and getting gold, magic items, or whatever coin. That facade just compounded that allure further of seeking that wanted prize in the tabletop element.
Just like the RPGs these days now, that have shifted from that mentality. So has video game RPGs. But the money getting thing is still there...but on a smaller scale. (maybe).
But to answer the main question at hand...yes, back in the days, it was about the killing, graverobbing, and pillaging. But like life...things will either change to keep fresh or folks will seek a different game setting to satisfy their gaming needs.
In my world...the need of coin has been replaced with a credit storage system. PCs are paid for speciality skills (besides being whatever class they are). And they have a monthly salary, plus bonus. And whatever they find along the way...is their 's (but taxable by the state

).
So...no more need to hear that pouch bag making noise when walking, or a seedy rogue eyeing that big purse. (Don't worry, the rogues have turned to higher crimes to get money).
And plus...depending upon who DM back then. If they pick up on this feeling I had and stil have to this day. They too, would have alter that 'gold digging' situation to something better.
Who wants to spend 6 to 8 hours or more...just 'fighting and pillaging' most of that time?
I gotta go with Scribble on this one. The game has become less focused on combat with every iteration, not more.
I look at my Basic/Expert system - virtually nothing outside of combat mechanics - no skills, no social resolution mechanics, spells are almost entirely combat related with very few utility spells; outside of thief skills, there is virtually nothing codified outside of combat.
1e - again, no social resolution mechanics, no skills (outside of the thief), most spells are combat related (although there are more utility spells), and some of the classes have to fight to gain levels at a certain point.
2e - Buckets of flavour, but, mechanically, not a huge departure from 1e. You have very, very basic skill mechanics bolted onto what is essentially repackaged 1e. A bonus XP chart that includes a couple of non-combat awards (although fighters are still only rewarded for fighting). But, there is definitely a move towards somewhat less combat.
3e - Arguably less flavour than 2e, but, more robust social skill mechanics (at least compared to what came earlier), more robust non-combat skill system in general, none of the classes need to fight to gain levels, and at least a nod in the DMG towards giving xp for non-combat encounters.
4e - Similar social skill mechanics to 3e. Codified system for extended skill challenges that take the game out of "real time" resolution in order to allow larger events to be resolved by the mechanics. Actual codified rules for awarding rewards for non-combat events.
Now, I totally agree that D&D has always been about the hack. Of course it is. Heck, all you have to do is compare the number of modules that can be resolved without killing, to the number of modules where killing is not only expected, but pretty much required in order to resolve the module.
The number of non-combat or even "combat light" modules, compared to the other kind, is pretty darn small. D&D is a game about combat and killing. You are best and most directly rewarded by the system for killing every enemy.
Does it have to be played this way? Nope. It doesn't. But, the system certainly pushes you in that direction.