I remember BG 1 & 2 good enough to know what is was about and if I liked it. I definitely don't remember it good enough to judge the writing in detail (mind you I also didn't play it in English back then). Also perceptions of me as a teen were way different than now, especially with experience working in the industry. That's why I'm careful. I've started playing BG1 again 3 years ago, but I stopped without finishing it. The impression was good, but again, before reviewing it in detail I would really need to sit down and play it.
As I mentioned before - while I as a player know that Shadowheart will have a story that explains it and that a part of the money I've spent on the game was invested in making her a key part of the game (not story), my character doesn't and except for the reason of being horny or very invested in everyone the character actually has no reason to listen to Shadowheart snap about until she is willing to tell it. Its the writers job to make me care about their creations and engage with them not mine as a player to find reasons to do so - its questionable/bad writing if its the second.
With Morrighan and Yen you don't need to like them. They are crucial to the plot and actively do something. Which gives you a chance to be exposed to more of their motives and story. You can love them or hate them, they still move something in the plot and have a reason to be there. Shadowheart is objectively useless to the plot beyond the artifact. You can even let her die in the prologue. In this case as a writer you better do a really good job of manipulating the player into giving a damn beyond just trusting the custom skin and marketing have done there part of the job to make the player curious.
I'm not sure about Yen, since it has been a while since I read the books, but Morrigan doesn't bring much to the table but a bad attitude. Her mother yes, but not Morrigan, at least for me. If you want to do the Dark Ritual maybe, but that is only at the end of the plot. Other than that, she brings you to Flemeth, but it is Flemeth later, who helps you and then shoves her daughter at you. You can even send Morrigan away. I btw feel about Morrigan and Yen as you feel about Shadowheart, they are annoying brats.
I personally had a much better connection to Shadowheart from the beginning. We have the same problem and we agree to work together and she is useful and has good advice.
That is what I mean with different opinions: you think, Morrigan is important, I think, Shadowheart is important. You are annoyed about Shadowheart and I about Morrigan and Yen. Let's agree to disagree, especially since I was talking about Sharran companions and not characters from other fabdoms in this case.
I played BG1&2 a year ago and still like the writing. While a few things would probably be handled different today, the writing is good overall.
