I am of the opinion that the game of AD&D 1E is itself heavily dependent on what happens during character creation. I think it is during character creation that the determination is made if the game is going to be a role playing game or a roll playing game.
The parameters set forth by the DM/GM in how to create the PCs sets up everything else. The more focused on heavy requirements on stats generated for character abilities starts the ball rolling. Does the Player get to have a more "generous" method of rolling stats or is there a very specific set of parameters that must be met to generate those numbers?
In my thinking, the more specific the parameters, the more the game will be a roll playing game and less role play.
Does the DM encourage or even require that the "story stats" be filled in during character creation? "Story Stats" being the information describing family history, where the PC comes from, relations, etc.... on the charter sheet.
To me, having this info provided sets up for a role playing game that takes more than just numbers into consideration.
Also, If character creation is a rushed or simplified process where most of the focus is on the character abilities, saving throws, the number driven stats, then the likelihood that it will e a roll playing game is greatly increased.
Characters created have little to no attachment with the Players who expect to have them die as easily as they were created and replaced just as easily.
Alternatively, PC's created using "Story Stats" as well as the number stats require Players to put more thought and invest more of their imagination into their creation. Thus seeing them die off easily and being easily replaced is not looked forward to by those who put more into character creation. All the more leading to Players expecting and anticipating a role playing game more than a roll playing game.
For many Players, I expect, using characters that were created to be easily replaced tends to the Players gaming in more of a "Chessboard General" style" and having little or no real attachment or interest in the characters.
For those with more involvement in the character creation process, they likely look for more "meaning" in the game and are looking for "glory and honor" as their PC takes on each challenge. More detail and content are expected to justify the major injury or death of such a PC.
I believe the DM/GM is responsible for setting the tone of the game. I think he or she should run the game the way they feel is best for the game. It should go without saying that setting the game up ad setting the stage, so to speak, should be done with making the best game possible with everyone at the table in mind.
It all starts with character creation.