If we accept that it's a collaborative endeavor at what point do you feel the player should modify their own expectations around character creation to better accommodate a DM's campaign/adventure/game concept?
I think there should be a conversation when a GM pitches a game, and folks should come out of it with expectations around character creation, rather than go into it with them. The player being inflexible here is just as problematic as the GM being inflexible.
What I see in this example is a single player who wants to play something that, at least insofar as the DM described his campaign concept... at the very least grates against the theme of a GoT-esque style game and could actually subvert them.
Sure, but 1) I don't think we can trust that OP to give us a really good idea of how things were presented, or what was in the conversation. "I want it to be like GoT," doesn't actually tell you much. Like GoT in what ways? More important to my point here, however is, 2) Being confused, frustrated, or indignant at someone merely asking means you probably weren't going into it open to collaboration.
And again, if your marketplace of players is large enough, maybe you don't need to collaborate so much. And that's fine. But one should realize that's an element of your situation, not a general entitlement GM's get to have.