Lyxen
Great Old One
And the assumption in this comment is that the DM is acting without regard to the players. But many DMs have a very good idea of what their players like about playing D&D. My current group have been playing together for 14 years now, every two weeks. We know each other and our gaming preferences extremely well at this point. So the DM does actually know what we like in a game, and has the authority to use that information to run the game.
Good point. In the case of our groups, many of us have been playing together for almost 40 years now, so we indeed know how to make games better for others within the framework of a particular campaign since we sometimes change paradigms and have long sessions 0 to make sure that we are aligned. Moreover, as most of the players are also DMs in other campaigns, it helps in knowing what players would expect.