Except many people are not giving opinions or feedback.
They're going HashTag-NotMyBG3 and making DEMANDS like 'Change The Name' or 'Remove the 3'.
That's not feedback; it's an overreaction that in no way helps the devs polish their game. You can say 'this sucks' but it's not constructive, and being angry it's not the game you (using a royal you; not YOU in specific) want is not useful feedback.
Saying 'the animations look stilted/silly' is feedback. Saying 'The spells don't look like they have oomph' is feedback. or 'The voice acting sounds a little flat' is feedback.
'Why is this BG3?' is not feedback. It's a complaint made by someone who's not going to enjoy the game unless the devs completely overhaul the entire thing.
To put it another way; I could go onto Modern Warfare's forums and complain that it's not a real FPS. But it's not feedback. It won't help the devs make the next one.
Of course its better to give specific feedback, but saying that someone is overreacting isn’t meaningful. They may dislike what they’ve seen to the point where minor precise feedback wouldn’t cut it, and so instead they show disappointment knowing that they’re not getting the game they dreamed off. There’s no point in trying to defend the game from that. It won’t lead anywhere. Just let them vent their frustration; it seems people have valid reasons for it, and it’ll pass eventually.