I’m probably really out on a limb here because I haven’t played in a tournament, but here goes some thinking out loud anyway.
Quotes come from James Maliszewski’s interview with Tim Kask
We also had other concerns, chief of which was how to conduct fair tournaments. Before the term came into vogue, we were marketing TSR virally; I was a perfect example. I played the game at a con, bought one and took it back to my group and infected them.
(1) Conventional play was a good way to market the game. (2) Tournaments were a good way to market convention play.
As the nature of the game dictated, it was meant to be only loosely bound by the rules as printed; they were originally meant as suggestions and guidelines. Finding 30 DMs to run a tourney for us was a big task in and of itself; finding 30 that played the game the same was impossible as each one ran his own campaigns as he saw fit.
(3) Tournaments required minimizing one of the strengths of the game. (4) It seems to me that marketing that minimizes one of the product’s strength is maybe not the best idea. (5) Furthermore, the adventures created for tournaments were often published as modules, but they were often not good models for non-tournament play.
Later tournaments had the participants vote on which of them had played their role best. This minimizes the need for standardized rules, but it also emphasized one aspect of the game over others.