Have you ever been in a situation where you wanted to do something in character creation that the DM didn't want, ultimately didn't get to do that thing, but stayed in the game anyway and had a positive experience?
Have I?
No. Not that I can think of. Not when I was on the player side of things, anyway. In large part because of one critical phrase, emphasis added:
ultimately didn't get to do that thing
Because there are a lot of ways to "ultimately" do something. Many of them involve doing it in a very different way than you originally conceived, or achieving it only over time, or by a means you had never considered, or in some other way being like, and yet also
unlike, what you originally thought.
That's the essence of reaching consensus. Both sides
ultimately get what they want. Neither side
defeats the other, unless you consider peaceful coexistence and cooperation a form of "defeating" someone. You are bringing to this the notion that the only "ultimate" end is one where one side gets everything they want and the other side gets none of what they want. Such zero-sum thinking is largely incorrect when it comes to pastimes where imagination is the primary involved activity and leisure time is the primary expended resource.
In short, is every DM who doesn't say yes to what you're asking for (eventually/mostly/whatever) a bad GM in your eyes?
That is not, and cannot be, "in short" for the above. They are
completely different things. The former is about my personal experience with DMs, and how they have handled such interactions. The latter is--as so many have done--trying to turn that into
"oh, so every possible way of saying no is wrong?"
I've already said--repeatedly--that there are ways to do this right. I just haven't actually seen people use them. I have given my players, for example, one such way of saying no: "I do not run games for evil PCs. This is not because I don't want you to run evil PCs. It is because I know I am not
capable of running an enjoyable campaign for evil characters. The things I am able to do that motivate and reward character behaviors won't
work for truly, sincerely evil characters. If you want to play someone who
was evil but is seeking redemption, even if they stumble along the way, that's perfectly fine. Or someone that is good, but suffers terrible temptation (and may, on occasion, succumb to it), that's fine too. But someone who is
just evil and comfortable with that...I can't give you what you need for that."
You will notice, here, that this has nothing--at all--to do with player preferences. It is purely and exclusively an issue of the limit of my capabilities as DM. I do not personally choose to play evil PCs for, pretty much, the same reason--it is not that I dislike them (some evil characters are actually quite compelling), it is that I will, sooner or later (and likely sooner), suffer an irreconcilable breakdown in my ability to roleplay such a character. I can do it with villain characters as DM, because I don't identify with any of them; I cannot help but identify with a character I am roleplaying, to at least a moderate degree, and it is simply not in me to identify with true, unrepentant evil.
I am, probably unsurprisingly, rather skeptical of the idea that any DM is, in any way,
incapable of running a game which happens to include at least one reptilian character that might have some kind of similarity or connection to dragons. I in fact find the very notion hilarious--that a single scale-covered character would actually
shut down a DM's ability to run a game? Yeah, I find that idea quite funny, like a DM incapable of running games for a character who wears yellow (guess they went to Green Lantern DM school).
I further find the notion, "I am incapable of running a game that accounts for my players' preferences" ludicrous--mostly because that statement reads identically to "I am incapable of running a good game." Noting, of course, that "accounting for" is ABSOLUTELY, POSITIVELY NOT the same as "perfectly kowtowing to the instant anything is said."
Because, as I said repeatedly but which apparently has always been ignored,
nobody gets a pass for acting like a petulant child. Nobody gets license for "my way or the highway." Nobody has unlimited agency.
N o b o d y.