A valid point. In the numerous works of fiction I have read that involve elves (and high elves in particular), they're often portrayed as haughty and extremely prudish, showing an excessive degree of disdain towards any race other than their own, sometimes even refusing to speak to them altogether. I don't know where this originated from but it seems to be the default for them at this point, both in literature and in media. With that in mind, the fact that my first impression of Lyriel was somewhere in between of "wow, easy there, you" and wishing she would just stay locked in her room forever was not surprising, but also not unexpected. From the moment she was referred to as a "high elf" and started being a brat towards... Tiana, I believe was her name? I knew what I was in for.
Still, as a dev/writer, I imagine one needs to keep in mind that not everyone partakes of works of fiction, less so that might include elves specifically, so they may not be aware of all that. If you don't, you end up creating an extremely irritating character that comes across as entitled, brattish and annoying "just because", and that tends to turn people off faster than I do when I walk down the hall naked.
Still, you are correct, the game is far from finished for all we know, so we may yet see a solid reason as to why she turned out this way... or not, who knows. I hope not, but maybe she really is just the stereotypical haughty high elf who knows nothing of how the world works and needs to wake up and smell the coffee, in which case I agree that this needs to be told in a more elegant and detailed manner. As it is, her background flashbacks felt a little... rushed? Very resumed. Like, you get bits and pieces of it, but not the whole story, and that can definitely skewer perceptions for the reader(s).
Ugh, forgive me, I rambled. As a writer, fluid, coherent storytelling is something I'm very passionate about. I suppose my "elf thing" also lowkey makes me want to ride to her defense despite also thinking she sounded like a complete bitch (at least at first).