Snarf Zagyg
Notorious Liquefactionist
I think of AD&D as "a set of tools I use to help make the game", not the game itself. I think of most RPG systems like that, actually. I also think this leads to a fair amount of mutual incomprehension with the diehard 'system matters' crowd.
"I made a RPG for running mysteries."
"Cool."
"So you'll use them to run a mystery?"
<reads rules> "No."
"But it's got these tools specifically for..."
"I prefer other tools. Or none, even, sometimes."
"But my game is about solving mysteries."
"I get that. Still no."
"Then your campaign won't be about solving..."
"Of course it will be."
" ... "
If it makes you feel better, the debate is a really old one.
As I allude to in my my other thread, OD&D was seen as a toolkit. As such, and this is a true example, someone could say that they were playing D&D using Runequest rules and a homebrew skill system. Mixing and matching was not just common, it was practically required; so you could have one table adopting more and more complexity and sub-systems, another adopting a universal method of adjudication, and another dropping it completely for a dialogue or freeform approach (as noted in ES, this was so common that in 1978, Traveller included it in Book 4 as an option without comment).
Of course, back then you also had designers complaining that people weren't using their systems, and were instead either using D&D, or were just borrowing aspects of the system to use in D&D.