I love all these characters and I want to play as them!
I totally understand the previous posts, but it's impossible to make a big game in which you can fully create your own character and to design the world to treat this character as this special person you made as a player. That's why always choose origin characters, even if I don't really like them (this was my problem in DOS, but I chose an origin character anyway) - because devs know them and can prepare the whole world and NPCs for them. They are not able to make the same for your potential vampire tieflings, paladin drows and other. All they can do they're already doing - making special lines for their classes and races, but it's all they can do. Maybe they could make origin templates, but remember that these origin characters personality, NPCs and plot would be copied too. You would always play as Astarion or Gale, the only reason would be your race, name, or sometimes class (I can't imagine barbarian Gale for example, his story is strictly connected to his class). And even this would create problems - what if we can meet, let's say, Shadowheart's parents in the next acts? If you change her race, devs would have to think about it too - they would have to create EVERY possible combination of her parents - like drow + hight elf, dwarf + dwarf, tiefling + tiefling etc.
Tabletop RPGs are great, because you can create your own character and experience the world as this very specific person, but sadly it's simply impossible in cRPGs.