The people I play Dungeons & Dragons with are friends with whom I've been playing tabletop RPGs for over a decade. In many cases I can predict some of their decisions in a role-playing game simply because I know them. In a small group with always the same players, much of what is going on is determined by the individual personalities of the people involved and the group dynamics. A DM is always to some extent a game designer, as you can run a D&D campaign in many different ways. But rules of good game design only get you so far, and at some point it simply becomes a matter of playing to the audience that you already know.

The game designers of a MMORPG don't know their audience individually. But they do have the advantage of being able to use statistical analysis. In my D&D group I know a guy who almost always will play a wizard because he loves that class. In a MMORPG with hundreds of thousands or even millions of players, personal preferences probably cancel each other out statistically and a statistical analysis will reveal more players flocking towards whatever class is perceived as being more powerful, more useful, or more fun to play. Over time there is a visible impact of for example nerfs of a particular character class on the number of people choosing to play that class.

For my D&D campaign it is sometimes a lot harder for me to get feedback. Friendship and group dynamics can get into the way of telling a DM that you didn't like a particular aspect of how he is running his game. And I do believe that is a fairly general problem, with many people running pen & paper role-playing games not getting nearly enough feedback from their players. It would take a lot of bad decisions as a DM before your group decides to quit and not play with you any more. The hobby has always had more people interested in playing than interested in being the DM, so there is a barrier to exit: You rarely know many possible DMs, so quitting a DM might mean not playing at all for some players. That doesn't exactly encourage DMs of trying to maximize player enjoyment.

I notice that especially in the discussions on various Dungeons & Dragons or other pen & paper role-playing games on forums and blogs, even YouTube. Some people have quasi-religious opinions on how a game of D&D should be run because of some rule that somebody invented 40 years ago without having had the benefit of seeing how it works out in practice (a general problem in designing a totally new genre of game). They have a certain vision of how things like "magic" should work that reflects more the fantasy world in their head than what is fun for the players around the table in this world.

I do understand the concept that art doesn't have to be popular to be good. I just don't think that "critically acclaimed but hated by the audience" is a good concept for game design if your audience is just that small group of your friends sitting around your table. You can strive to raise the level of the game on your table, but ultimately you need to provide a fun game to the people who play with you.