Celebrim
Legend
every time they introduced a new player option, it was usually by taking away something I'd thought all PCs should be able to do (minus some caveats like not tightrope walking in armor) just to give it back as a special option you could take. When the Dungeoneer and Wilderness Survival Guides came out in '86 and included skill proficiencies letting PCs do what I'd always thought they could do anyways, I was unsurprised.
I'm not sure I would go that far. Nothing in the 1e DMG implied that characters had proficiency at more than a list of 'secondary skills', and that in itself implied that everything that wasn't part what you'd conceptualize as one secondary skill was silo'd off as something another character could do. Maybe more importantly at no point did AD&D ever address how likely someone was to succeed in anything. This would have left people to ad hoc what the odds of successfully canoeing a boat through rapids were. All the NWP's did for me is convince me that whatever the odds were, someone who was proficient with boats should have higher odds than someone who wasn't.
For something like the Acrobat skills, none of them struck me as the sort of thing ordinary people would be able to do. I mean, sure, people could jump but most people couldn't "long jump". It was clear that this was an area of skill, it was just not clear that every area of skill needed a whole class or that the approach was helping solve the problem of how to handle non-combat propositions fairly.
From early on there was always this idea that you could propose a character do just about anything, especially anything you could imagine an ordinary person doing, but unless you had some class feature that indicated otherwise, there was no guarantee you'd be good at. Anyone could propose to move quietly, but that didn't mean you were quiet. Anyone could propose to catch a fish or engage in an act of simple carpentry, but no character was just assumed to be successful at it. In any event, the game really didn't tell you how to handle those propositions. You just went with something, and what you went with varied very much from table to table.