Well thank you, at least, for answering the question in a straightforward manner. I find it curious that you ascribe both an attitude (pettiness) and a motive ("MY etc.") to what was otherwise a minimal-context example. Might I ask why (and specifically, why the assumption of a negative attitude and a controlling motive)?
The DM isn't choosing this to create any kind of experience or give any kind of focus to the game; you said, verbatim, "which means that considerations of genre, theme, and tone are already and automatically precluded." To me, that is equivalent to saying that no part of producing an enjoyable game for anyone
except the DM factored into that decision. It is, simply, saying, "My tastes are more important than anyone else's here." And since it is, in fact, being
openly given without any further consideration (since we're talking about DMs that don't pull fast ones on their players), well, how would
you feel about being openly told, "I simply dislike the aesthetic of that, so I'm not letting you or anyone else play one"? It communicates a lack of interest in or respect for the thoughts and desires of players who have any preferences of their own--a unilateral declaration of "nope, I don't like it, so it's not allowed."
Let's say I cop to all of this. Here's the question I really want answered—the thing I've been badgering Hussar and Minigiant about—why is the latter a bad thing for a DM to do? What's the reason this is something to avoid?
Because, if the DM's job description requires respect and trust from the players, the DM ought to act like they deserve that trust. Caring about what other people want, and not simply unilaterally dismissing the ideas, desires, or preferences of others, is a necessary (but not sufficient) step for earning others' trust in
any situation. Whether or not a negative attitude is
meant by such brusque behavior, it is communicated, because
being so brusque is, itself, a demonstration of that lack of concern for others.
Respect is not just a two-way street. It is a relationship. That relationship has implications. Among these are listening, caring, and the pursuit of common ground. To choose
not to listen, to demonstrate you do
not care, to not merely ignore but
shun common ground, is to damage that relationship.
Er, no. It has nothing to do with whose imagination is better and everything to do with the DM's loss of enjoyment. You can imagine the best dragonborn possible, but I still can't stand them. There's nothing you can do to prevent that loss of enjoyment. In game terms, it doesn't matter how high your skill bonus is or whether you have advantage, since you don't even get to roll if there's no chance of success.
Again, that's false. I can imagine you doing all kinds of interesting things with dragonborn. You don't get to accuse a DM of badwrongfun just because there's something that will deprive him of enjoyment and he doesn't want to experience it in his game.
See above, Max. I absolutely think it does, and just saying "er, no, it has nothing to do with that" does not substantively respond to my core argument: the DM claims a position deserving respect, so she should act accordingly, and absolute unilateral dismissal of preferences
purely and exclusively because they aren't
her preferences is a negation of that respect, not a reason to give it.
Edit: And again, because I have had to reiterate this literally every time I say something like the above, compromise IS NOT ALWAYS POSSIBLE. Some situations, it really, truly can't be resolved, and that's OKAY. It is COMPLETELY FINE for the DM and the player to put in a good-faith effort, and come away not actually being able to resolve the problem, at which point I grant that it is the player's responsibility to respectfully exit, or choose differently. I am, I was, and I presumably always will be only arguing that this conversation, to determine whether compromise is possible and to find one if it is possible, is necessary for a healthy DM/player relationship. It is (one part of) how the DM demonstrates that the trust and respect vested in them is warranted.
I'd roll my eyes if a DM told me they'd excluded half-orcs because of the icky stuff and wouldn't consider it any more valid than the other reason. But I would accept the decision and after my eye roll I'd just finish up my character and move on.
I mean, I've known people who have gone through some Bad Experiences. I wouldn't blame them if part of dealing with those Bad Experiences was avoiding things that might, even in passing, only historically, and only by implication, tangentially relate to that stuff. As an example, one of my current players was emotionally manipulated and abused by parental figures for many years, and is
still struggling to throw off some of the naughty word, naughty word programming (metaphorically) beaten in. I hadn't expected a corrupting and mind-controlling spirit-thing to set off those alarm bells, but it did, sending that player to the hills until we forced the issue, talked it out, and forged ahead. Thankfully, because my players are awesome and this player specifically trusts me a great deal, we were able to overcome the problem in a highly satisfactory way, which I think was overall helpful. Yet I can at least conceive of a situation where someone isn't ready for that, may not ever
be ready for that, and just doesn't want even the risk of a hint of a whiff because PTSD is a bitch and can completely ruin a night (or even a week) if set off unexpectedly.
Edit 2: Lemme put it this way, MGibster. If someone has an almost-uncontrollable urge to vomit at the smell of lemon because strong lemony scents or flavors remind them of how a naughty word parent used to lock them up Harry Potter style, would you truly begrudge them saying they don't offer citrus-flavored sodas, not even La Croix, while gaming (or indeed at any other time) and ask you not to bring any into the house? It's not that there's that much chance something could happen. It's that even a very small chance of projectile-vomiting over the table is too large a chance to accept, when the chance could be zero.