Fanfiction gets a badrap, but there's absolutely nothing inherently bad about it. It's just that there's a stereotype of what fanfiction is that mainly exists among people who don't interact with it on more than a casual level. There's a lot of bad fanfic out there, but there's a lot of bad media out there in general, of course it's going to be relatively greater when the barrier to entry is non-existant. Fanfic is also an easy point of entry for people who are just starting out trying to write and be creative, since by defenition it provides them with a starting point that they can easily build off off. Everyone's gotta start somewhere, and I remember that on an episode of his podcast, Brandon Sanderson was talking to a friend of his and they admitted that they basically started out by doing what amounted to fanfiction. But good fanfic is still just good writing, and it's good writing born from a particular type of passion and personal investment.
But generally I think that the character writing is the place this game shines. I suspect that if it weren't quite as good, or the performances not quite as strong, then people would more clearly see all the faults and issues with this game. But having read the article, it kind of seems like the writing there worked in spite of Larian's style and creative instincts, not because of it. I keep having to rein my opinions in on their negativity and remind myself that creating anything is hard, creating games is hard, creating a game this big and objectively ambitious and having it work at all is HARD. For all its flaws and problems, the fact they managed to produce a thing that works this well at all is something to be appreciated. They worked hard to create this, there was a lot of passion and effort behind this game, and that should be recognized. All that being said... the results do feel remarkably sloppy in a lot of place, and it's hard for me to feel much regard for Larian and their skills as creators. It feels like they failed at what they were actually trying to do, stumbled into something else that works, and don't realize they failed in the first instance. But that's an ungenerous assessment because this wasn't just pure luck, this was people putting a lot of time and work into doing a thing.