So I think I'm seeing the disconnect.
When I proposed Thorin, my proposal is pretty much so that I wrote: a one or two sentence outline. Now, I was not aware you run a specific setting or AP (if I was, I would adjust to fit that, but in lack of knowledge, I assume a standard general setting).
That is what makes it an excellent example of how the modern GM is backed against the wall & left with nothing. There's only so much a GM can expect their players to read
(almost nothing) or listen to
(maybe a sentence or two) before they lose interest & stop listening. The player doesn't need anything from the GM & as a result has no incentive to listen to the GM's attempts to impart knowledge about the setting & campaign. Even If you knew that I usually run a particular setting there's no way to impart all of the baselines to as player in the tiny bit of time still afforded to the GM & IME the extremely low odds of a player fully knowing the setting in ways that won't require me to correct areas like your thorin example needed correcting on is almost certain to result in the exact kind of reaction as the one you demonstrated originally if they do anything but throw the world out the window & accept whatever "backstory" a player offers without question.
As to the Thorin example fitting poorly into eberron... and darksun.... and so on.... I have seen it come from a player more than once and never once has it gone well. There is just too much to correct about the differences in setting baselines... The GM is not allowed to infodump or a player shuts down & gets upset if there are any misunderstandings leading to problem areas. The GM can't expect anything they find or write to even get skimmed. If the GM says x is bad so it would need to be something fitting
(as I did) the player either digs in with anger or suggests some other ill fitting tolkeinism/FRism/etc that leads back to the beginning
Further, I'm not married to the Thorin concept even at proposal, it's generally my first choice and my preferred one in this hypothetical example, but I can be convinced to move on IF my next option is equally cool. (If my idea is an exiled noble who seeks glory and a return of his homeland, I might be convinced to shift it to a priest who is interested in reclaiming a lost temple of his faith beset by demons, but I'm not interested in "you're a farmer who discovered goblins carry gold and opted to try his luck in the local dungeon").
This thread itself says otherwise.... "
Really, it doesn't sound like I get to much say in my character at all. ", "T
he most classic dwarf character in literature. We're not talking about a half-dragonborn/tiefling bloodhunter/hexblade here, about as normal, and safe as a PC can be. It's literally the trope-setter for many. Yet I just got denied" No the GM can not tell a player what the replacement is because the GM has nothing to offer like they once did andif they do they are taking away player choice "
assum[ing] the worst of [their] players and any attempt to wrest even a modicum of agency from the DM is tantamount to a coup attempt. Rather than reward a player for engaging with your world and providing plot hooks, you assume I am some Mary Sue trying to make the game all about [the GM's] own story." or any of the other condemnations of heavy handed GM'ing through the thread since
this simple post pointing at the other side of the coin that many had been rah rah rah'ing. The GM in modern D&D often needs to go into the discussion as some kind of transcendent hyperelevated being engaging in 12d chess with a barely tolerant quick to aggress player & do so without the slightest misstep
Additionally, just because Thorin has this long term goal, it isn't at the exclusion of all other goals: he can be seeking allies, experience and items of power and then at some point in the future, decide to assault the "dragon" in the keep and complete his goal.
You might as well have stated that the GM should ignore your stated goals and admitted that the whole section of your backstory was pointless filler but you previously said "
I will return the favor: your world's history and lore will mean nothing to my PC. If you expect me to care about your world, I expect you to care about my character." showing why the GM needs to correct that up front rather than expecting it to happen during gameplay. The GM in modern D&D no longer has the tools that would have once allowed them to make some effort to direct the problematic goal in other directions and certainly can't do so lest they be accused of "passive aggressively trying to direct the players instead of honest engagement with them" with a side of "passive agressiveGM'ing due to not having prep available and so trying to redirect the party away from the not prepped places/things or the GM having prep available" as happened earlier in 1077 &1084 after I gave broad examples of how a GM could use the tools they no longer have in
this post.
Lastly, my goal is that, a goal. The DM is free to design around and flesh out the idea. Perhaps the dragon was killed by adventurers in the meantime and a different worse baddie moved in. Perhaps Thorin's memories painted events different than what they were (although, I'd still like something resembling my goal: to spend sessions building up to a major event in my PCs life only to have another group of dwarves kill the dragon and establish a peaceful kingdom off camera that we just walk into is anticlimactic to the point of trolling).
Problem being is that you didn't ask the GM if you could make that your goal, you declared it along with a bunch of other worldbuilding ele,ents and reacted with extreme negativity when problems were explained. The GM is expected to accept anything & it's on them to make it work with an empty quiver.
This, of course, is all permeated on the idea I get a choice in this at all. When people responded to this, only saw one poster say, "your idea is cool, but what if we adjusted this..." And two responses that said, "hmmm... Probably not. And if so, you're going to jump through a lot of hoops before I consider it. But mostly no." Which isn't a great negotiating point.
Then again, I prefer "yes, and" or rarely "no, but" as styles of gaming. So hard a "no" really disconnects me. If Thorin doesn't work, propose a counter offer. Which brings me back to random generation. Random chargen is a hard no. It says "you weren't lucky enough to play what you wanted" and worse, it allows the DM to block things without the negotiation (I'd have let you play your paladin, but the dice didn't. Not MY fault...)
The GM can't do that because it's not treated as a discussion, they aren't treated as an equal with any say, & even shifting the player from "x is my goal" to "can X be my goal" is a bridge too far into heresy.
I know there are terrible players who demand primadonna attention. There are terrible DMs too that use their authority to power-trip on their players. No set of rules, be them empowering to DMs or PCs, can fix bad players.
When a GM makes good faith efforts to explain how a pitch thrown at them is problematic and is barraged as happened earlier with vows of murderhoboism in a world that means nothing it is by definition back to a demand. Nobody has a PHD in background negotiation or similar & the GM shouldn't be expected to have one or see if maybe just maybe if this obvious flashing collection of warning signs will maybe not turn into the trainwreck it's shaping up to be just like all the times it happened before. At that point it's the GM's fault for not engaging in the "honest engagement" that they have serious barriers to even attempting as displayed since the thorin example