Ok, as this seems to be taken as standard, I stand corrected and had the wrong idea regarding "Old school".
But if the fitting GM is a so big part of the parcel, it will be hard to recreate for a newbie from a rules system alone.
I agree... with two caveats.
1. The early days of the hobby were built by people (designers and players) with heads stuffed with SF and Fantasy novels and stories. These were the original sourcebooks of the hobby and people could roll out the monsters and environments they'd read about with their friends. (I have this theory that novels and stories provided better inspiration for such play than movies and TV, but it's just a gut hunch, and I can't justify it at all. My bad.)
2. The hobby grew out of a larger hobby of miniature enthusiasts and war gamers cross-pollinating with fans of SF and Fantasy. That is, the first players (at least the DMs, if not the Players as well) of OD&D, original
Traveller, and other games were not starting "cold." Not only where the first RPGs an outgrowth of a hobby already in full swing, but
the players were part of that hobby as well... with practical and cultural support for understanding and playing RPGs already in place. (I touch on these ideas somewhat
in this post.)
So, yes, it would be difficult for a a "newbie" approaching OD&D from the rules alone. But most people in the first years were not approaching the rules alone -- they were approaching them with an entire hobby and culture of play supporting them.
Later games would (in my view) shift in this regard. They become more and more independent of the war-game/referee-driven/reading-driven play of the early years. These games were more self-contained, with the rules nailing down what would previously been
assumptions of how to play and developing setting and adventure material built specifically for the game.
[Edited to Add: I'm not saying this shift was good or bad. I'm saying it
happened. That is all.]