This is not truth. If you read the negative reviews, you will see a lot of reasonable arguments. But only because someone is criticizing something, doesn't means that people would't buy...
Negative reviews huh? Was the game buggy? Not really. Did they change the engine or mechanics? Nope, still the crappy infinity engine. Did they change the scenery? No, still good old Baldur's Gate, plus some really interesting new places. Did they change the characters? No, pretty much the same friendly faces plus some new ones. Poor writing? Let's say different, more actual, since there is about 20 years between games. Still, not particularily bad. Story? It was good for an expension, and even tied to some other IE game.
Si if everything above is at least good, and you still bash the game and give it negative reviews, than you probably had way too high expectations for this, wich doesn't mean the products is bad, it just didn't live up to your standard.
Again, it is just my opinion, not talking about you specifically 👍