Many groups use modules exclusively, in which case the GM doesn't "create" any adventures and is in fact a referee in the contest between the PCs and the adventure.
Typically the GM still chooses the module, no? Maybe the players are handing the GM the module, or the GM is rolling a die to randomly determine the module used. But then the GM made a choice to agree to the method of module choice. Somewhere along the line, a choice, an act of will on the GM's part, is involved.
And, somewhat more directly - the GM is making
all the choices for one of the sides. Claiming he's a referee is rather like claiming the guy in the black and white striped shirt with the whistle is only a neutral referee, when he's also calling all the other team's plays.
What I don't understand is why this is so difficult for people to believe.
It isn't at all difficult to believe. I used to play in that line when we took up AD&D way back when.
...how is that the gm's fault?
It is only "fault" if the players don't have fun. There is no need to try to dodge "fault" if you're pretty sure folks will, overall, like the results. If you can see it coming, and really think that in the long run they'll be happier for having gotten wiped out, you should stand up proudly and support your decision to do that. There's only a need to shift blame to the players if you think there's something wrong with the proceedings.
I was in a campaign once, where the entire party got wiped out in the first session. We stayed up into the early hours of the morning, and made new characters, with most of us changing classes from what we started with, and plunged into the same dungeon. Two decades later we still play those characters once a summer - we are very happy we had that TPK, because it added a bonding experience, and we're pretty sure we like the second party more than we'd have liked the first - better characters with more entertaining personalities the second time around. We are all happy with the result, and the GM.
Another time, a different group, a different game - the party ended stuck in a position where the only way out of a situation was unacceptable to the players. It was, in essence, a TPK that the players could not have possibly foreseen (and thus could not have chosen to avoid) and pretty much ruined the game if allowed to stand. The GM owned up that he'd misread us, took responsibility, and rewrote the ending of the adventure to something that was a reasonable compromise. We continued playing under him for years afterward because he could take responsibility and act accordingly.
But really, that's not the point of what I was trying to say earlier. I was more reacting to the sophistry about it being "some other game". There's two leagues - one uses pinch hitters, the other doesn't, but neither tries to claim they aren't both playing baseball.
That doesn't mean you need to use a pinch hitter. Just don't try to disown the other league.
