I agree with both sides of this argument to some extent or another. I have no problem headcanoning a backstory for my characters; my Seladrine Drow ranger Yvonnel for instance is a bounty hunter specializing in hunting and killing Lolth-sworn drow who try and make it to the surface for whatever reason. But I also think that the game should do more to help you anchor your character in the world. Even something as simple as what Pillars of Eternity did and giving you the choice to have a conversation with someone about your past would be a satisfying way to do that. And the absence of anything like that honestly just feels worse to me because of the depth and availabilty of multiple origin characters with deep backstories of their own.