And that protagonist was for the most part a [generic charname]. The narrative never made me care enough about the main character, the way I for example cared about the Nameless One. If this was a book or a movie, I'd not bother finishing it. Fortunately, as games the BG saga had more than the boring protagonist, like the exploration and fun combat.
That "boring protagonist" was you, whoever you decided to be. Everything was centered around letting you have the choice of deciding who you were and every part of both games, by and large, were part of describing who you actually were.
Comparing with The Nameless One is a bit unfair, in part because he was many people over the years, and in part because story-telling and atmosphere is the one thing Planescape Torment did better than probably any other game before and after.
I don't think it would open a can of worms, I think it would have been a good design choice for the game. And if it would make the writers notice the "fakeness" of the shadow thieves vs. vampires choice, even better. Because that part of the plot feels like it was done only to create some narrative drama, by giving the player a choice between two evils. The way it is implemented, it only makes the [generic charname] look dumb, because faced with such a choice they don't even attempt to find a non-evil route (because the writers didn't bother creating any). This sort of bad design is also very prominent in ToB, where again your character has no agency and does as Melissan tells you.
The writers were almost certainly well aware of the fakeness of shadow thieves vs vampires, but adding a different option would have required time to write and implement and test. And BG2 didn't have an endless budget, so messing around with this entire section just to add a third option would have been a lower priority than making other parts of the game work. There's a lot of stuff that was started but never got finished, and there was probably a lot more still that was only ever on the drawing board but never got any further than that.
You're right about ToB, though. I didn't like it all that much and I don't think all that many people did. It's too railroaded, too linear, with nowhere near enough player freedom.
